HUMHUB: How can i give specific users file permission?

Question

Three Questions

1. Example Groups:

1. Admins (#All Files)
2. Colleagues (#File1, File2)
3. Partners (#File3)

// Info: # <- for Permission.

2. And whats the difference between:

Username->Administration->Users->Tab("Groups")

and

Dashboard->Members->Tab("Members")

?

// 3. Info: Tag "Humhub" dont exist, what to do?