ZCBS_GRP is the code of a cost centers hierarchy that is used in the Co$ta - Dashboard. This is a grouping of the Level 2 of the ZCBS hierarchy. 

The Level 1 of the ZCBS_GRP hierarchy is used to group: 

• GBU cost centers in GRP_GBU
• Function (=CBS excluding the function SBS) cost centers in GRP_FUNCT
• SBS cost centers in GRP_SBS

The Level 2 of the ZCBS_GRP is used to group functions "shared" and functions "corporate" that are separated in the ZCBS hierarchy. 

The level 3 of the ZCBS_GRP is the level 2 of the ZCBS hierarchy

You can display the ZCBS_GRP hierarchy in SAP using the transaction KSH3 - Display cost center hierarchy (only in controlling area Z013) 

You can also use the report FC - Cost centers master data to display all cost centers with their assignement in the hierarchy ZCBS_GRP. 

• Level 1 of the ZCBS_GRP = [C_GBUFUCT] Function grouping in BW
• Level 2 of the ZCBS_GRP = [C_GRPFUCT] Function in BW