How do I use the jump accelerator (freeform mode)

I'm in free form mode. I know that one can't just select any waypoint in the Gangrin cluster. But I don't know which point to click manually. Thanks for your help

Zoom in all the way on the l-point you want to depart from (liberty l-point to go to gargin), then select zoom one more time to select 'jump destinations'. You can now choose where your destination is from that l-point. You will see many lines going out from the lpoint and one of them is highlighted. You will also see the name of the destination somewhere on the screen. Just hit right or left to scroll through destinations until you get the one in gargin. Then hit whatever button you normally hit to select stuff in the navmap. You're now ready to fly through the l-point from blue to red.