Hi Harry
There are other options - the suggestion was just the easiest solution that works in my case.
Using the profile summary card (in 13+) to display adding custom profile fields to users with the permissions to view the field
The summary card if shown when a user is clicked on in Engage and also in a courses under Participants
Custom profile fields can also have visibility settings
When using the report builder the visibility of the users depends on whether the user viewing the reports has the visibility allowed to view the fields
Regards