Assuming the question "how have you been?" is in the sense of "how are you?", you can use one of the above translations. If, on the other hand, it does refer to the past, I would say "Hvordan har det vært?" OR "Hvordan gikk det?" (this refers to something specific discussed earlier).
Note however, that in any case, unless you know the other person very well, asking "how are you" is not common in Norwegian!