I have no trouble with grouping so that one or more set field entries go into one group (Group A) and everything else goes into another group (Other), but what if I want to allow users to determine what goes into Group A based on a parameter selection. 

 

For example, we sell parts which are all grouped into a number of different franchises.  I've written the report so that all parts from two of these franchises go into Group A and all other parts go into Other.  How can I use a parameter to allow the report user to select which franchise(s) go into Group A, leaving all the rest to go into Other?

 

Thanks