By default, SailPoint will only reassign certifications from a terminated user to their immediate manager, if that manager is active. It won’t automatically move certifications to the manager’s manager if the direct manager is also terminated.
To make certifications go to the manager’s manager, you need to set up a custom workflow. This workflow should detect when a manager is terminated and automatically reassign any pending certifications to their own manager (the next level up). This isn’t available out of the box—you must create the workflow for this scenario.
Check that your user profiles have manager and manager’s manager assigned, and that lifecycle states are updated to “Terminated” when someone leaves.
Refer : Workflow for Re-Assigning Manager when they are getting Terminated - #3 by udayputta