The Inspirator group feature means that an Inspirator can invite other Inspirators to be part of their group (i.e. linking Inspirators together hierarchically). This is useful with e.g. Sports Clubs, where the Club's profile can link all of their players "under the wings" of the club.
It's possible to create multiple levels of hierarchies, e.g. League - Sports Club - Players.
How do I activate the group feature?
You might already have it. When you created your profile and selected "We are a Group", then you have it. If you are not sure, you can check it at your Account Management.
In the picture above, the profile is an "Individual", thus not a Group. By clicking the "Show details" button, you will find a way to activate the group capability:
How do I invite another Inspirator to be part of my group?
Just navigate to their profile and select "Invite to the group..." from the dropdown menu:
Once they accept the invite, your latest update will be shown in their profile, and vice versa.