Currently, the only way to see which issue is related to which Epic is identified by the Epic Label, and the mark on the side of the issue when viewed in Planning mode. Also, the issue is in a separate part of the screen than the Epic.

It would be more convenient if the user can drag the Epic around, and the related issues will follow it as it moved. This will benefit users that would like to focus on Epics in their GreenHopper.