Filtering Reference Based on Selected Product

defineField({
      name: 'products',
      title: 'Products',
      type: 'array',
      of: [
        defineArrayMember({
          name: 'productWithSelectedVariants',
          title: 'Product with selected variants',
          type: 'object',
          fields: [
            defineField({
              name: 'product',
              title: 'Product',
              type: 'reference',
              to: [{type: 'product'}],
              weak: true,
            }),
            defineField({
              name: 'variants',
              title: 'Variants',
              type: 'array',
              of: [
                defineArrayMember({
                  name: 'variant',
                  title: 'Variant',
                  type: 'reference',
                  weak: true,
                  to: [{type: 'productVariant'}],
                  options: {
                    filter: ({parent, document}) => {
                      const productID = document.products.find(
                        (product) => product.variants == parent
                      ).product._ref

                      return {
                        filter: `_type == "productVariant" && references($productID)`,
                        params: {
                          shopifyProductId: null,
                          productID,
                        },
                      }
                    },
                  },
                }),
              ],
            }),
          ],
        }),
      ],
    }),