Invite new people
First of all you need to go to the people directory by clicking on the people directory
located at the bottom of the people panel
or you can use a shortcut by pressing G
on your keyboard.
From here you have to click on the action button, which is located at the bottom right of the screen,
which looks exactly the same as the following image:
A modal window will appear where you can fill out one or more emails and select to which groups
the newly invited people should have access to.
Emails have to be unique!
You will only see groups you have access to unless you have admin
rights, in that case you may select even groups that you are not a member of.