By default, Community Builder allows changing user groups only in the Backend's User management pages, but not directly on the profile in the Frontend. Backend access, on the other hand, gives the user a lot of power, which you often don't want to grant to normal (i.e. non tech-savvy) administrative staff.

With this plugin, the administrator can set up a usergroups profile field with ability to assign/remove certain user groups to other users in the Frontend. The field configuration specifies which user groups shall be editable and which are not touched by the field. For example, if you have groups "Member", "Former Member", "Administrator", "Associates" and "Board", you can configure the plugin so that one can only assign/remove group membership of groups "Member" and "Former Member" in the FrontEnd, but cannot assign, change or remove the other three group memberships.