Can you allow members to add other members?


Hoping someone can answer this for me.

I want to create a site where someone will sign up and have the option to add other members of their team who would be able to login and edit the same profile/content as the original member?

I have found a site that seems to have this functionality and its running S2 so I assume there is something I can do?

There is this which seems to be perfect but I am not sure if its still supported?

Thanks in advance