By creating User Groups and assigning Users to them, you can limit certain Users to only see and create data for other Users in the same User Group, by using Drop-down lists containing Users. Furthermore you can control the visibility of certain Custom Fields and also the options in lists for each User Group. This could be useful for departments, topleaders or companies with a high employee number.

Go to Configuration --> Main settings --> Basic settings and activate User Groups in your system. Then you can access the "Manage User Group" button.

You create an User Group by clicking on the "+" icon in the right side of the page, and choose the name for the group.

To assign a User to a User Group, go to Configuration --> Users, and choose the wanted User, and thereafter select the correct User Group.