[Mauiusers] FairShare - splitting usage between multiple groups

[Craig West]

In Maui, is it possible to split the fair share usage between 2 or more 
groups?

What I mean is, given the following setup:

User1 is a member of Group1
User2 is a member of Group2

User3 is a member of both Group1 and Group2

I would like User3 to evenly split its share between both Group1 and 
Group2. That is Group1 and Group2 should both accumulate FairShare 
information when that user is running.

If this is possible, how is it done? I tried to use group_list, but 
apparently you can only have one group defined.