How do you teach 4th limit breaks

[Mercen-X]

I don't think i learnt his hammer blow i moved straight to Satellite Beam

I once gained Meterain before I learned Clim Hazzard, it was a real annoyance. You have to go back to that lower level to learn Hammerblow.
Then there are these items you have to find, one for each character (except Cait Sith who only has two limits) which is also a real annoyance.