Depends on your control scheme. If its Mouse, simply right click the rank and the menu comes up with Hierarchy Settings as one of the options. With controller, scroll to that rank and hit the X (Xbox controller) or Square (PS3) and the same list will come up.
EDIT: Shouldn't have deleted your original question in case someone else is having the same problem, they'll be able to know what was asked. To anyone that is interested, he asked how to change a ranks hierarchy settings in a Free Company.
Edited, Aug 29th 2013 7:39pm by DragonBourne