Implement new data in existing Data Model / Build relationship

Hi Everyone,  

I have a problem with implementing new data from the data reports into my Power Bi model.  

I used to have one center table which connected all my other data tables: 

Now, I have to implement some newly formed Sub-Groups (which are already in the data tables, however not yet in the center table, as I would like to be able to filter on the Sub-Groups on all pages). 

I already tried to: 

• add the Sub Group into the center table, however, the error occurs that the existing relationships fail due to duplicates (multiple EMEA's) 
• set up another center table for the Sub Groups only, however, I get the error that the new relationship would introduce ambiguity between my old relationships 
• merge them together in one center table through a conditional column, however, the filtering does not work at all then 

As I would like to filter on all pages of my Power Bi report, I want to keep the Account Group center table. Is there a way to 'plug' the new data table into the existing center table without any errors occurring? (seems for me to be the easiest solution) 

Or is there a way to set up two center tables which connect all other data tables and lets me filter on the two different groups? 

Are there any other approaches or suggestions?  

I would appreciate any help.  

Thanks in advance.  

Best regards, 
Patric