All Users List View is a fairly recent enhancement to assist administrators and help desk analysts to quickly find a user's sessions across a cluster.
To activate, Right-Click on the Cluster and select "All Users List View":
NOTE: due to the high level of communications required to query each server in the cluster and compile the sorted list of users and sessions, the All Users List View does not automatically refresh. You need to use the Refresh action explicitly to refresh the all-users list.
The View will then change to a Summary / Detail flow report, which each User that has active sessions displayed in the leftmost column and that user's sessions then displayed below:
Note that like the Server Details View, you can Right-Click on a user's session and View or Stop that session. The View option will display the Built-In Terminal Emulator which you can use to interact with the session if needed.