This feature is very useful when dealing with what protocols are running on the server. To find this, click on Summary | Protocol Hierarchy in the Wireshark menu. A protocol hierarchy of the captured packets will open, as shown in the screenshot:

From the security point of view, it will give a high-level glance at all protocols that are happening over the Ethernet system. Network administrators use this information to harden the system configuration; for example, if the administrator found a DCE protocol running in the production system, after seeing this protocol hierarchy he can raise an alarm to stop this service.