If more than one image group is on your screen, first activate the group upon which you would like to perform the sort by clicking on the group's title. The title bar of the image group will be highlighted when it is the active group.
Go to the Main Menu and select Group, and then select Sort by. This brings up the sort by tool on the left side of the Group Workspace.
Using the sort-by tool you are able to sort the images by four different hierarchal sorts. These are the primary, secondary, tertiary and quaternary sort fields. Use the drop-down list box of available data fields to select how you want your fields to be sorted. Select the new sort fields and select apply.