Once you're in a patch group, one of the ways you can move from patch to patch is by using the "increment" or "decrement" button. If you stored your favorite patches in the "user" patch group, then you should be able to move between them like that. The xp-30 also has a control jack for a foot pedal which I believe you can assign to simulate either the increment or decrement buttons.

Someone correct me if I'm off target here.