How to set "Historical Rate Override" against a SubConsolidation Entity

Summary

How to set "Historical Rate Override" against a SubConsolidation Entity

Content

Hi all

I want want to know if it is possible to set How to set "Historical Rate Override" against a SubConsolidation Entity.

Example we have a

- Parent A

    - SubConso B

        - Child Entity 1

        - Child Entity 2

...................................

The system allows use to set rate under the base entities, but does not allow us to set it against the SubConso.

Question: How to we set the rate against that subconso and if not possible, is there a workaround?

Thank you 

Nouria