In order to be able to decide who is allowed to be member of the group you must be the contact person of that particular group. To appoint a contact person you must go to the group page.
Select the menu point in the context menu on the left. You will be directed to the group editing area:
Click the button in the contact persons section. You will be directed to a list of all members of the virtual network. Select the desired member. This contact person is then automatically equipped with rights and can edit the members list.
Now if there is an application to join the group the respective contact persons and the group founder can decide whether or not the aspirant is allowed to join. An e-mail with the membership application is sent to all contact persons and group founders. In order to confirm or deny aspirants you must, as described above, go to the editing area of the group. In the bottom area of the screen there is a list of all group aspirants. By clicking on the checkmark you confirm the new member. In order to deny membership select the next to the aspirant. You also have the choice to message the aspirant for possible questions you may have.