You might be able to achieve this by creative use of PDM_LIST, PDM_SET and PDM_IF macros. First, create a PDM_LIST clause where you get the list of users in one of the groups where the userid matches $cst.userid (or whichever field you wish to use) and limit the results to one. Then within the list you use PDM_SET to set a variable of your choosing to a value you'll test for later. Then create a PDM_IF where you test for the variable you chose for the value you used and do on functionality in the true branch and the other functionality on the else branch.
Just be aware that urgency is a required field on cr object so you'll have to have default values for the once that's not supposed to pick their urgency.