Required Properties for Group Dimensions 
You can report consolidated results in multiple group currencies within a single entity structure. The G dimension for group members provides multiple currencies for a group member.
You can also assign a G dimension to ownership applications.
Note
A G dimension must be assigned to an ownership and a consolidation application. You should assign both an R and a G dimension to a consolidation application but you should assign only the G dimension to the ownership application referred from the consolidation application. You cannot assign both an R and a G dimension to the same ownership application.
End of the note.
More Information
Member Behavior Using Dimension Properties
Business Rules Management for the Microsoft platform or Business Rules Management for SAP NetWeaver