If your former supervisor has retired or moved to a different company, call or reach out privately on social media to see if they might still be willing to act as a reference for you. You can still use that person as a reference.
Sometimes you may have no idea where your former supervisor has gone. If you worked at a larger company with a human resources section, it will keep files about past employees. A potential employer can always contact them to ask for details about your time at the company.
Your Questions Matter
A career services staff will review it and respond via email. If it's something that can help others look for work, explore careers or succeed on the job, a version of your question and answer may even be added to the site.
Your privacy is important. If your question is published to alis, your identity will remain anonymous. Your email address and any other personally identifiable information will not be posted to the site.