MDG Filter on BAdI Implementation

We have MDG-F in production and use a custom Z implementation of USMD_WF_AGENT BAdI.   Enhancement Spot = USMD_WF_AGENT.

We are now activating MDG-C and it is using another implementation of the BAdI (MDG_BS_CUST_WF_AGENT_ERP).  The customer implementation came in with a filter.  Filter is MDGC_ERP = AGENT_FILTER.

Our problem is that the MDG-F Z implementation does not have a filter and it is getting picked up by default for both MDG-F and MDG-C. 

I've been doing some research, but cannot figure out what/where this value would get sent.  I wondered if "MDGF_ERP = AGENT_FILTER" would work, but tested and it does not.

We are using "other MDG workflows" for MDG-F.

Can anyone point me in right direction?

Thanks,

Keith