AR Credit memo approval over multiple operating units

Hi,

I have recently implemented Advanced Collections for one of our operating units. In order to  make use of disputes I have setup the AR Credit Memo Approval Workflow and have created the Receivable Role as a responsibility and pointed the MO: Operating Unit to the required operating unit.

Now I need to role out the same functionality, but to a different operating unit. My problem at this stage is: I cannot point the same responsibility to multiple operating units. I also cannot setup another responsibility which points to the 2nd operating unit as I only have one place to enter the Receivable Role and one workflow.