Changing Course Behavior Based On Previous Completion

We have a number of courses that we require employees to take year over year from a compliance standpoint. We’re moving to allow employees to test out in years 2 and beyond. 

I’d love to keep this as a single course rather than building out two versions. I'd like to use Javascript to query the LMS and references past course completions to determine whether to give the learner a pre-test or not. 

I've been able to successfully access completion status of the current session (basically have you completed this course or not), but not previous completions. I'm working in Saba. Am I way off base? Is this something that's possible?