Service based logging can be enabled via the command line or using Citrix Scout installed by default on XenDesktop 7.5 and later versions. Citrix Scout lacks some feature logging; it doesn't enable Citrix Broker Service agent logging.

So, it's always better to enable your environment's service-based logging using the command line.

An example of a command to enable Citrix Broker Service Log is as follows:

BrokerService.exe –Logfile "C:\XDLogs\Citrix Broker Service.log"