Users tab is built into CB GroupJive. It can only be moved by moving it in GJs template files. Specifically the below template file.
components/com_comprofiler/plugin/user/plug_cbgroupjive/templates/default/group.php
The Users tab has no access control. You're not controlling the access of those tabs specifically, but you're shutting off the entire access to those plugins.
Access controls would again need to be done at the same place in the template file. Group content access is intended to be based off the group type.
It's best to make a new template folder (e.g. mytemplate) and copy group.php to it then within GJ configuration select your new template. This will avoid your changes being lost on update.