The Single Central Register that can be accessed under Admin Menu will always display all users on the system, including admin users who are not employees as well as members of the Support or Onboarding team from Access.
It is not possible to filter this menu or remove admin users from being displayed.
However, we would recommend giving access to the Single Central Register only to users with full access to the system. All other users should instead use the Single Central Data Report.
For more information on how to give access to this report please follow the guidance on our article about the Single Central Register.