Hi Ting,
After doing the required equation you can use the option "Update from Excel" from Schedules tool to import (synchronize) those values back to OBD. Please refer to the below screengrab.
HTH!
Regards, Sayan Acharyya
I also checked the "Compact" selection tree option. In my opinion it's not worth much. In the project I opened it just lists all of the models, without any sub-compartimentation. I'd think its too little hierarchy, but maybe it will work for you.