Narrowing results of collection list

If you click on my site preview link, then use either the 2nd or 3rd drop down at the top to select a collection, you will see a collection list will display.

These are artworks from a collection.

Multiple artworks per artist can currently be displayed.

We would like to instead display only one (prefer random) per artist, without having to removing the collection tags from the other artworks in the CMS.

Can anyone please help me with this?


website preview

Here is my site Read-Only: [LINK]1
(how to share your site Read-Only link)