Where do I manage my users’ settings in Keystone Client (validation files)?

This is managed under General System Administration -> Security/Menus/Access Rights -> User Maintenance [VALIDATION file] (KF0045).

Select the Look Up icon to view current users (Active users display first):

For a more detailed article about user settings, please review this article as well:

One of my Keystone Client users transferred to a new position and department - what security settings need to be reviewed and adjusted?