How to write Payment approval rule in BPM to add approval group

Hi,

We currently have a BPM rule that looks at the Payment Process Profile so that when a payment is imitated it hits two approval groups for approval if it is not a specific B/U. What we want to do is add an additional clause to the end of it so that if the TOTAL value of the payment process request is over X then a 3rd group is added.

I've started this by having two BPM rules, one only has 2 groups in and the other has 3 groups (the same first 2 plus the extra group). I assume that I need the the first to have a clause that says if the TOTAL is < or = to A and the over needs to be more than B