How to Sort the different levels of a Layout Group by an activity code

Hello!!

I need your help here. The issue is that I have defined a Layout with my activities group by an Activity Code called Location. So my activities now are shown group by the location they are assigned. Now I would like to sort all this different locations by their finis date, because right know are sort by the way the Activities code Values are difined in my Activity code.

I do not know how to do it,please could anybody help me with that??

Thank you!!