Hi
In the webUI, go into "Dashboard" -> Traffic Analysis then to filter by a client, you will see in the summary row something like "HOSTS 10 " - click on the "10" (as it is here) and then you can choose applications or destinations etc (and you will see it's filtered by host IP)
From the CLI, use:
show datapath session table <ip>
show datapath session dpi table <ip>
hth
-jeff