Validate Job field on Position Details based on Progression Job

Summary: We have a requirement where we need to validate the Job on Position Page(for Request a Position Change) based on the old Job's progression job. For example if there is a job Clinical Nurse I and the progression Job for Clinical nurse I is Clinical Nurse II. So we want if the Job on position is Clinical Nurse I then it should only be changed to Clinical Nurse II, or it can remain Clinical Nurse I. We want to put a hard stop if the Job is changing from Clinical Nurse I to Clinical Nurse III or any other