You can associate a product with multiple navigable and non-navigable collections all at the same time.
To add a product to one or more collections:
On the Catalog page, navigate to the product you want to work with and open it.
On the product’s Collections tab, click the Edit button.
Select a collection from the list. You can filter the list by typing or pasting some text in the Collections box.
The filter control matches letters or numbers that you type, wherever they appear in the name or ID, not just at the beginning. Usually, as you type more characters, there are fewer matches. When you see the item you want, select it.
Click Add Selected.
(Optional) to remove a collection from the Included Collections list, click the x at the end of its name. To remove all collections from the list, click the Remove All button.
Click Done when you finish adding collections.