The idea behind saving a circle is to keep a tap on the audience you most care about.
Once you have saved a circle, you can click on the circle analytics icon to view the users, sessions and the time spent in this circle
You can also subscribe to daily and weekly alerts for your circles statistics and changes from last day.
You can go to the segments reports to see the users and session time of users falling in that segment. Also, you can export data for different segments from our export button.