We havce an requirement to keep the previous supervisor in an user attribute value while any user's supervisor is getting changed via HR IDC. We followed below -
1. Created a custom attribute (Type User - Previous Supervisor)
2. Created a trigger to update the Previous Supervisor with Old supervisor value while any changes detected in Supervisor in T_MASTER_ENTERPRISE_USER table
We can see the trigger is working when we update the value by query, however not working after identity collection and unification. The Previous Supervisor filed values is getting null itself.