You can link the new case to their old data by entering their previous UID on the “Was the person previously employed at UCLA?” screen when starting a case.
When bringing a candidate in from Recruit for an Appointment case, Opus allows users to enter the candidate's UID to find their previous record if they were previously employed here. Doing so will allow Opus to add the Appointment action from the current case to the Academic History of this person if they had previous appointments in Opus.