Hi Pramad,
Both Total and Group are used in case of consolidation mostly.
Group: You can define one "Dimension Value" to all the other dimensions values of which amount you want to group together during consolidation. This you can think as how we use "Consolidated Main Account" in General ledger
Example: Lets you have Dimension Value 1,2,3 4 and have one shared group dimension "X" , now you can map "X" to all 1,2,3,4 dimension values in Group field , due to which X will have amount from all 4 Dimensions
Total: Also works in similar way when you want to add amount from other dimensions to the single dimension.
Both will only after enabling following parameters :
