Create the new collection and make note of the collection’s handle. The collection’s handle can be seen by clicking ‘Edit Website SEO‘ within the collection itself.
Then, go back to your product and add a new tag that specifies the collection’s handle:
meta-related-collection-handle-name
So in this example, since the collection handle is featured-products, so in our example product: ‘Mixed Stripe Tee Dress’ the tag to add would be meta-related-collection-featured-products.