An optional function found in the LMS course settings that would allow you to sync two separate course certificate expiry dates.
Use case would be subsequent different knowledge level courses where the next course requires achieving at least an equal or greater knowledge assessment test. Once the user achieves a higher knowledge certificate, the previously achieved lower level course expiry date can be automatically synced and extended to match. This will avoid nuisance notifications of requiring re-achievements of lower level courses if tests were taken with a time gap and/or the higher level course is valid for a longer term.