You can create a separate page listing all the required data from all users. Then give access to that page only for administrators so that normal users won’t be able to go to that page.
For configuring the user roles, please see documentation for security settings.
For setting association of your entity with System.User. Select entity in domain model, double click to open properties, go to associations tab and click new as shown below
Now in select entity screen, type User and you should see System.User entity. Select it.
In your scenario 1 user should be associated to many objects of your data entity