You can create user groups from the "manage user groups" option. There, the user can create groups and add users to them. To access this option, the user must:
Expand the list of options for the "user" menu located in the main menu and select the option "manage user groups".
Click on the "new" button located in the upper right corner to create a new user group.
Click on "users x user group".
Click the "new" button to add a new user to the group.
Select the user ID and the group ID to which you want to add the user.
Repeat the process with all the users you want to add to the group.
Save.
User groups allow you to restrict the selection processes a user has access to, if desired.