Share 'Synchronously sort data while creating a set'

I have two sets of data of the same size, one of is a list of points and the other contains generic data.  I can create a set from the list of points to remove all duplicate data, but I also want to be able to see which items in the generic data list correspond to each of the unique items in the set.  In other words each of the unique items in the first data set will have a corresponding list of…