So you have all of your level 4 skills except for that front hip circle?
So the thing with bars is... its ALL about practice. Very few people are natural for bars. While on the bar you use your muscle memory which comes from a lot of practice. By this I mean that by practicing this skill you will eventually get it.
Have you tried bending your legs? For many people, this is what makes the difference. You should bend your legs at first and eventually when you get the skill try to straighten them out. Also try to watch videos on youtube for front hip circles, this helps a lot of people. Make sure you watch everything in particular the wrist movement.
Hope this helps! Good Luck!