The user can identify their access viewing the bottom righthand corner of their screen:

There may be occasions where External User is displayed, this is a user that doesn't have a designated role within the Document i.e. Site Admin (access all areas) or a user that isn't within the project team as they are completing a specific task.

The access level is set at Document level this may mean working on multiple Projects/Sites a user may have varying access so the user role on the screen my switch.