User permissions required: ‘View users’ or ‘Modify users’
The Projects page is accessible via the 'Manage Access' tab on the Admin console. The Projects page allows you to select a project to see (and search for) other users in that project.
Users can select the correct organisation via the drop-down menu on the top left of the page (where it says 'All projects').
In the projects column on the page, users can see the other projects that each user belongs to, as long as they themselves are also in those projects.