As the collection owner or Super Admin, you can search a collection in the Library to see what items are restricted or not restricted. The choices are: Not Restricted, Media Items Restricted and Media and Records Restricted.
After performing an Other Criteria advanced search for either media restricted or media & record restricted, an additional drop down list of users and credentials that are potentially excluded from the restrictions will be displayed on the left hand side. The list should be located on the left hand side of the results, right below batches.
When you click on a user name or credential from that list, the result will show all items that the user has access to within the restricted items.