When you click the Group By button, you can activate different sorting methods to organize the devices in the topology view.
Panorama Group By Icons
The following figure shows the Group By icons.
The subnet grouping option is only available when the devices in view belong to more than one subnet. When devices are grouped by subnet, each unselected subnet appears as a cloud. Click the plus sign on the cloud icon to expand the subnet and view the member devices and their status.