Help setting up a course with 5 audiences

I always start by asking if there is a specific reason that you want to have a single Storyline file that contains 5 courses?

In the meantime, if there is enough shared content to warrant building as one then one way to do this might be to start with a landing page where a learner chooses their role.

Using branching, you could send the learner down the relevant path and using variables you would be able to serve up the relevant question bank for the learner's role.

The challenge comes in marking the assessment as passed for your compliance purposes. I suspect you would have to direct all 'passed' quizzes to the same 'end of course' slide and send completion to the LMS based on a trigger on this slide. If a learner fails then you'll have to either allow them the chance to resit or send them to an 'end of module' slide that has a failure message on it. If there are 5 different quizzes I'm not sure how useful any information on the quiz score is going to be when it is displayed in your LMS. As the LMS will only read from a single results slide you'd have to specify which one. 

Personally I'm not keen on throwing a load of courses in to one file. I usually find that any perceived time saving on maintaining and updating content is lost when trying to crowbar in workarounds that serve up ever-so-slightly different content to multiple learner groups. I would always opt to build the most complete 'base' course, and once it has been approved, duplicate it and make any relevant changes to make each of the other versions.

There is another older discussion on the quiz issue here.