Translation:Who does not want a working relationship?
I'm pretty certain it's nothing to do with one's job, since att fungera is to function, and att arbeta is to work (at a job).
I don't think "working relationship" is wrong here, but I think most English speakers would interpret this is a professional relationship. A less ambiguous translation would be a "functional relationship" and that's probably the natural way to say it in English. But of course this section is about participles, so maybe a "functioning relationship".
Is arbetande a word a Swede would use, anyone? Or would an adjective like professionell be the natural choice? I'm thinking of a working man, a working holiday, a working visa, and so on.
I agree. "Working relationship" feels like something of a fixed phrase to me, but I'm not sure if I can explain how I'd use it. I feel like it's the sort of thing you'd hear if someone was trying to convince you that two people (or groups) work closely and effectively. If someone described, say, a romantic relationship as a "working relationship" it'd feel like they were saying their relationship is reliable, but not necessarily that it is loving.