The type of licensing you have affects the reports and analytics options you have available to you.
When you have a firewall with an NSM Essential license, only the most basic reporting coverage is provided.
Reporting is limited to a small set of Summary reports and the matching Details reports. With the NSM Essential license, you don't have the ability to drill down from a tenant or group view of the data, nor do you have access to all the reporting and analytics options. To see details on a specific firewall you need to navigate to Firewall View and then select Monitor.
The NSM Advanced license provides additional coverage: You have access to many more reports and drill-down capability to log sessions. You also have different views of the information. Tenant reports let you see the amalgamation of a tenant's devices in a single view. Group reports are also available. You can see data combined, based on a group that you set up.