Spaces can be used to divide your overall company account into multiple sub-accounts called Spaces. Each Space has separate profiles, groups, dashboards and also its own limits. Still, user management works across all your Spaces.
You can add a new space here. Once you have more Spaces activated and you are assigned to more than 1, you can easily switch between them by clicking on your user on the left-right bottom corner:
You can also manage which users are assigned to which Spaces. To do this go to the Admin settings then click on "Users". Next to the users' name, click on "Edit". You can just tick the box next to the Space to which the user should have access, choose their user rights or which groups of Profiles they should see.