Is there a mapping (or relationship) between the 8 stages of Jhanas and the 4 stages of Enlightenment.
This could be a very debatable topic, but really keen to know this.
No, they aren’t related. You can reach the base of perception/non-perception and not even reach stream entry. Case in point, the Buddha’s own original meditation teachers both achieved rarified arupa jhana but weren’t arahants. There’s also plenty of canonical evidence that advanced meditators have been outright evil people or, at the very least, engaged in some pretty horrific acts. Milarepa, for example, used his advanced siddha power won through meditation to commit murder.
So in short, just because you are an accomplished meditator doesn’t mean you’re enlightened. Likewise, a very enlightened person can have an advanced degree of insight, but little to no jhana experience. The only overlap is nirodha samapatti - the so called 9th jhana. I forget which path level it requires specifically, but I’m pretty sure it’s anagami or “non-returner”.
If there's a mapping, I never heard about it. But just from the common sense, you have to be a stream enterer just to start practicing meditation correctly.
People do all kinds of wrong meditation and call some stages of that the first jhana, the second jhana and so on, but in reality you can't do jhana if you have not entered the stream of the right practice by attaining the right understanding.