This is available in several locations. By request quick new links where added (panel on the left can be disabled). Please review the below configuration.
GJ > Config > Categories > General > "New Category" and "New Group"
GJ > Config > Groups > General > "New Group"
GJ > Config > Tabs > General > "New Category" and "New Group"
GJ > Config > Panel > General > "New Category" and "New Group"
GJ > Config > Overview > General > "New Category" and "New Group"
Most if not all of them are "Disabled" by default.
Based on your feedback I have been looking for a similar way to get rid of the "Back to overview" menu item that appears when all groups in a category are listed:
There's no parameter to remove this. You'll need to edit GJs template files found below.
components/com_comprofiler/plugin/user/plug_cbgroupjive/templates/
As all of GJs frontend is template based it's possible for GJ to be completely redesigned to fit whatever purpose you want.