Success and Line Manager Role

Summary

Our Line Managers currently don't see Succession

Content

Succession was initially configured for only HR to have visibility to Succession.  However, now we want our line managers to see it.  Our line manager role is a custom role and I have added several privileges but I still cannot get succession to work as a manager. We are still using the classic view as of the moment.

Any  ideas on what privileges I might need to add?