diff --git a/packages/api/src/Domain/Products/JsonApi/Filters/CollectionGroupFilter.php b/packages/api/src/Domain/Products/JsonApi/Filters/CollectionGroupFilter.php
new file mode 100644
index 000000000..9b4ba272b
--- /dev/null
+++ b/packages/api/src/Domain/Products/JsonApi/Filters/CollectionGroupFilter.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace Dystore\Api\Domain\Products\JsonApi\Filters;
+
+use Illuminate\Database\Eloquent\Builder;
+use LaravelJsonApi\Eloquent\Contracts\Filter;
+use LaravelJsonApi\Eloquent\Filters\Concerns\DeserializesValue;
+
+/**
+ * Filter products by collections within specific collection groups.
+ *
+ * Accepts a nested array keyed by collection group handle, each containing
+ * an `id` key with comma-separated collection IDs. Produces AND logic
+ * between groups, OR logic within a group's collection IDs.
+ *
+ * Example: ?filter[collection_groups][group-1][id]=1,2,3&filter[collection_groups][group-2][id]=4,5,6
+ *
+ * @phpstan-consistent-constructor
+ */
+class CollectionGroupFilter implements Filter
+{
+    use DeserializesValue;
+
+    private string $name;
+
+    public function __construct(string $name)
+    {
+        $this->name = $name;
+    }
+
+    public static function make(string $name): self
+    {
+        return new static($name);
+    }
+
+    public function key(): string
+    {
+        return $this->name;
+    }
+
+    public function isSingular(): bool
+    {
+        return false;
+    }
+
+    /**
+     * Apply the filter to the query.
+     *
+     * @param  Builder  $query
+     * @param  mixed  $value
+     * @return Builder
+     */
+    public function apply($query, $value)
+    {
+        if (! is_array($value)) {
+            return $query;
+        }
+
+        foreach ($value as $groupHandle => $filters) {
+            if (! is_array($filters) || empty($filters['id'])) {
+                continue;
+            }
+
+            $ids = is_string($filters['id'])
+                ? array_filter(explode(',', $filters['id']), fn ($id) => $id !== '')
+                : (array) $filters['id'];
+
+            if (empty($ids)) {
+                continue;
+            }
+
+            $query->whereHas('collections', function ($q) use ($groupHandle, $ids) {
+                $q->whereHas('group', function ($q) use ($groupHandle) {
+                    $q->where(
+                        $q->getModel()->qualifyColumn('handle'),
+                        $groupHandle,
+                    );
+                });
+
+                $q->whereIn(
+                    $q->getModel()->qualifyColumn('id'),
+                    $ids,
+                );
+            });
+        }
+
+        return $query;
+    }
+}
diff --git a/packages/api/src/Domain/Products/JsonApi/V1/ProductSchema.php b/packages/api/src/Domain/Products/JsonApi/V1/ProductSchema.php
index 801cb8e5c..54c4d25b4 100644
--- a/packages/api/src/Domain/Products/JsonApi/V1/ProductSchema.php
+++ b/packages/api/src/Domain/Products/JsonApi/V1/ProductSchema.php
@@ -7,6 +7,7 @@
 use Dystore\Api\Domain\JsonApi\Eloquent\Sorts\InDefaultOrder;
 use Dystore\Api\Domain\JsonApi\Eloquent\Sorts\InRandomOrder;
 use Dystore\Api\Domain\Products\Builders\ProductBuilder;
+use Dystore\Api\Domain\Products\JsonApi\Filters\CollectionGroupFilter;
 use Dystore\Api\Domain\Products\JsonApi\Filters\InStockFilter;
 use Dystore\Api\Domain\Products\JsonApi\Filters\ProductFilterCollection;
 use Dystore\Api\Support\Models\Actions\SchemaType;
@@ -317,6 +318,8 @@ public function filters(): array
 
             WhereHas::make($this, 'collections'),
 
+            CollectionGroupFilter::make('collection_groups'),
+
             WhereHas::make($this, 'tags'),
 
             ...(new ProductFilterCollection)->toArray(),
diff --git a/tests/api/Feature/Domain/Products/JsonApi/V1/CollectionGroupFilterTest.php b/tests/api/Feature/Domain/Products/JsonApi/V1/CollectionGroupFilterTest.php
new file mode 100644
index 000000000..d58e838c4
--- /dev/null
+++ b/tests/api/Feature/Domain/Products/JsonApi/V1/CollectionGroupFilterTest.php
@@ -0,0 +1,242 @@
+<?php
+
+use Dystore\Api\Domain\Prices\Models\Price;
+use Dystore\Api\Domain\Products\Models\Product;
+use Dystore\Api\Domain\ProductVariants\Models\ProductVariant;
+use Dystore\Tests\Api\TestCase;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Lunar\Models\Collection;
+use Lunar\Models\CollectionGroup;
+
+uses(TestCase::class, RefreshDatabase::class)
+    ->group('products', 'filters');
+
+it('can filter products by a single collection group', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+
+    $collectionA = Collection::factory()->create(['collection_group_id' => $group->id]);
+    $collectionB = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $matchingProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $matchingProduct->collections()->attach([$collectionA->id]);
+
+    $nonMatchingProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][category][id]={$collectionA->id}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany([$matchingProduct])
+        ->assertDoesntHaveIncluded();
+});
+
+it('can filter products by multiple collection ids within a group using OR logic', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+
+    $collectionA = Collection::factory()->create(['collection_group_id' => $group->id]);
+    $collectionB = Collection::factory()->create(['collection_group_id' => $group->id]);
+    $collectionC = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $productA = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $productA->collections()->attach([$collectionA->id]);
+
+    $productB = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $productB->collections()->attach([$collectionB->id]);
+
+    $productC = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $productC->collections()->attach([$collectionC->id]);
+
+    $ids = implode(',', [$collectionA->id, $collectionB->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][category][id]={$ids}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany([$productA, $productB])
+        ->assertDoesntHaveIncluded();
+});
+
+it('can filter products across multiple collection groups with AND logic', function () {
+    /** @var TestCase $this */
+    $groupCategory = CollectionGroup::factory()->create(['handle' => 'category']);
+    $groupSeason = CollectionGroup::factory()->create(['handle' => 'season']);
+
+    $categoryA = Collection::factory()->create(['collection_group_id' => $groupCategory->id]);
+    $seasonWinter = Collection::factory()->create(['collection_group_id' => $groupSeason->id]);
+    $seasonSummer = Collection::factory()->create(['collection_group_id' => $groupSeason->id]);
+
+    // Product in categoryA AND seasonWinter — should match
+    $matchingProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $matchingProduct->collections()->attach([$categoryA->id, $seasonWinter->id]);
+
+    // Product in categoryA but NOT in seasonWinter — should NOT match
+    $categoryOnlyProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $categoryOnlyProduct->collections()->attach([$categoryA->id, $seasonSummer->id]);
+
+    // Product in seasonWinter but NOT in categoryA — should NOT match
+    $seasonOnlyProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $seasonOnlyProduct->collections()->attach([$seasonWinter->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][category][id]={$categoryA->id}&filter[collection_groups][season][id]={$seasonWinter->id}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany([$matchingProduct])
+        ->assertDoesntHaveIncluded();
+});
+
+it('returns all products when collection_groups filter value is empty', function () {
+    /** @var TestCase $this */
+    $products = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->count(2)
+        ->create();
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl('/products'));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany($products);
+});
+
+it('returns no products when filtering by a nonexistent group handle', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+    $collection = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $product = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $product->collections()->attach([$collection->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][nonexistent-handle][id]={$collection->id}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedNone();
+});
+
+it('ignores groups with empty collection IDs and returns all products', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+    $collection = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $products = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->count(2)
+        ->create();
+    $products->first()->collections()->attach([$collection->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl('/products?filter[collection_groups][category][id]='));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany($products);
+});
+
+it('returns no products when filtering by nonexistent collection IDs', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+    $collection = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $product = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $product->collections()->attach([$collection->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl('/products?filter[collection_groups][category][id]=99999'));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedNone();
+});
+
+it('returns only matching products when mixing valid and nonexistent collection IDs', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+    $collectionA = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $matchingProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $matchingProduct->collections()->attach([$collectionA->id]);
+
+    $nonMatchingProduct = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+
+    $ids = implode(',', [$collectionA->id, 99999]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][category][id]={$ids}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany([$matchingProduct])
+        ->assertDoesntHaveIncluded();
+});
+
+it('does not duplicate products belonging to multiple collections within the same group', function () {
+    /** @var TestCase $this */
+    $group = CollectionGroup::factory()->create(['handle' => 'category']);
+    $collectionA = Collection::factory()->create(['collection_group_id' => $group->id]);
+    $collectionB = Collection::factory()->create(['collection_group_id' => $group->id]);
+
+    $product = Product::factory()
+        ->has(ProductVariant::factory()->has(Price::factory()), 'variants')
+        ->create();
+    $product->collections()->attach([$collectionA->id, $collectionB->id]);
+
+    $ids = implode(',', [$collectionA->id, $collectionB->id]);
+
+    $response = $this
+        ->jsonApi()
+        ->expects('products')
+        ->get(serverUrl("/products?filter[collection_groups][category][id]={$ids}"));
+
+    $response
+        ->assertSuccessful()
+        ->assertFetchedMany([$product])
+        ->assertDoesntHaveIncluded();
+});