Column Sorting of Matrix on Web

I have created a Matrix that is using columns to divide the data between multiple branches.

I need the ability to dynamically sort the data based on details from within one of the columns i.e. sort the whole table by branch 1's sales while still showing the data from other branches. The default sort only sorts on total rather than the divided data.

Is this possible? If so how do I set it up?

Thanks for your help.