When you’re hit & sent flying upward, you should DI back to the stage. Don’t use your jump. Your opponent is likely to edge guard you & hit you. If this happens, you’re sent further & you won’t be able to recover well enough to make it back, but saving your jump allows you to come back, plus an up+b can get you back on stage or holding the edge.
Let’s say you jump went you’re sent flying, you only have the option to DI back & up+b. No jumps are given to you since you already used it.
Don’t use your jump unless you really need to (get sent flying downward).
Its doesn’t depend on your percentage or power of the attack. It depends on whether you use your jump or not. & jubeh is correct. You get another up+b, but you don’t get another jump assuming you used it.
If you’re grabbed from you’re up+b while trying to make it back on the stage, you get thrown back out, you get you’re jump back.
In Melee, Falcon’s/Ganondorf’s up+b gave you the ability to use you jump again if used. Not sure if thats still the case in Brawl…
Hope this is clear & helps.