Multiple Business Groups impact on Responsibilites

We are setting up a new instance on 12.1.3.  We have two Business Groups (India and US) and several ledgers and OU's (India, US, Canada, etc) which will all be 1-to-1.  I've setup a global hierarchy with both BG's in order to support cross charging.  The India OU falls under the India BG and all other OU's fall under the US BG.  I've also setup a global security profile tied to the global hierarchy that would allow access to all OU's (the starting level is above the BG's).

I assumed I would be able to setup a single responsiblity to access all OU's much like you can with standard MOAC, but with multiple BG's this doesn't seem to be allowed.  It appears that even if HR: Cross Business Group is enabled, you still have to set HR: Business Group to allow access to a single BG.  For us, this would mean that we need two responsibilites to allow access to the OU's under the two BG's.