place it anywhere in the group header.
It will reset your L9PriorToToday and L9LessThan30 to 0 in the header then on each detail section it starts to roll up again, then the next GH sets it back to zero and repeats.
you can even suppress it so it does not clutter your display
Edited by DBlank - 10 Oct 2014 at 3:58am