The Custom Space User Management -plugin (CSUM) gives Space Administrators ability to manage users and user-groups associated to their Wiki Spaces.
Using this plugin Space Administrators can:
As space administrator, choose a space from the dashboard or just click on the globe icon next to the space in the dashboard and go to Browse Space -> Manage Users/Groups (tab)
In this page, you can add a group, add a group and specify users, create multiple groups (enter a comma-delimited list of group names).
When you have selected or created a group, you can add users into it and modify groups restrictions on current space.
For Aalto usernames you must add the whole username with domain i.e. email@example.com
You can manage your groups permissions either by clicking on "edit space permissions" link at the bottom, or by going to space admin (tab) -> permissions.