If you have a lot of different Desktop Groups, it can be a challenge to see all of the active sessions in your farm. Unlike the XenApp console, you can’t just simply click the higher level folder and see all users active in your farm. Typically, you would have to select each desktop group and view the users in it separately. Not good at all as the number of groups increase.
Another way to quickly view all the active sessions is to use the Advanced Search. Click Advanced Search, Find Sessions By User and leave the name blank. This will return a list of all active sessions across Desktop Groups.