As a Content Editors or Content Manager:
  1. Navigate to Core.
  2. Select Content (and potentially Additional content types).
  3. This will list the Content Types and Categories the Manager or Editor have been given access to. 

 Note: After making a user a Content Editor or Content Manager, they need to log out of the system completely, then back in before the role changes will update. This is the same for impersonating - a Platform Manager must log out completely, then back in before impersonating a user to see role changes.