This is the swivel mechanism for the high pressure air at the center of my Campbell Hausfeld automatic retracting air hose reel. That hose is crimped directly on the swivel mechanism instead of adding negligible cost with a threaded fitting.
The upshot is that the hose is not replaceable by itself if damaged. And of course parts are not readily available. Throw out the whole thing instead and buy something new. Assholes.
I dont think it's a banjo fitting. Fairly certain banjo fittings are not meant to move once tightened down. Another poster is right though, if you take it to a hose shop, they will probably be able to cut the old hose off and crimp a new one on. Just google "hose shop in [your town]" and there's likely to at least be one in the next town over. I live in a mid sized city and there are like 3.