Flute Question ~ ! (:?

when playing flute music there are 3 different pitches for most notes like the b flat for instance. the lowest b flat is below the clef and would be the lowest b flat you can play on flute, the middle octave of b flat is writen where you would normaly see a b flat on the clef and the high b flat would be the one above the clef, there's also a really high one above that ... but that one takes some time to master, i played flute for 5-ish years and still have trouble hitting it. if i could draw it out i would ... hope this helps :)