I'm not sure I can explain this very well, but I'm wondering what kinds of roles you can typically get in to that are not part of the intended purpose of the workplace.
I'm thinking large organisations such as a large sixth form college, a large county council department or HQ for a large commercial enterprise.
I don't mean roles that you specifically started in, such as accounting or HR. I'm thinking more like your role evolving to take in more and more time as, say, a Safeguarding Officer or Union Rep.