Go to the TABLE tab, select REPEAT REGION icon, then in the menu manager that pops up, select SORT REGIONS, select the region you want to add a sort to, ADD, FORWARD or BACKWARD (depending on your preferred sort order), then select the column that you want to sort by.
Actually I think you would get better visibility if you posted in PTC Creo Elements/Direct instead of the top level PTC CREO. Unfortunately is in a sub-category of PTC Creo which is used for Creo Parametric. There have been requests on the PTC Community Help forum to clarify the topics in which has worked on doing. I think there is still a need to create clear "home" for each distinct software.