There’s already existing suggestions addressing the playlist aspects of your suggestion.
- artist / album level → List Playlists containing artist on the artist's page
- track level → Identify tracks that are members of playlists
You should already see artist collections on an artist page in both Plex Web and Plexamp.
Corresponding collections are however not currently listed on album or track collections – so maybe let’s focus your suggestion on that section and comment/vote in the existing suggestions with regards to the playlist scope, in order to help us avoid distracting or cannibalizing votes.
Edit:
There’s one more related suggestion, focusing on listing all collections where an item appears on that item’s details page.
List the collections containing media (movies or tv shows) below their description
