Could anyone explain what is group control (GC) and sub-group control (SGC) in Teleperm XP of Siemens DCS?

We are operation and monitoring with Siemens TXP... I would like to know about this concept to know about our pump's control system. Please help me.

 

Group control is for the main activity co-ordinator like Gas turbine start up, Sub group control is allocated for different activities during starting up or shutting down like SGC lube oil, SGC fuel, etc.