Leaders can be added into User profiles (Admin > Users) to denote managerial reporting lines or for the purpose of mapping Approval pathways on the platform.
When creating or editing a Workflow (in Admin > Workflows) you then have the option of selecting to have an Approval Workflow be sent to an approver's Direct Leader:
The Leaders option will still default to the Direct Leader of the requester, however they can opt to instead select their Leader' Leader or other Leaders in the chain (leader of leader of leader, etc).
What happens if a Requester's Leader changes?
Under Admin > Settings > Workflows there is an option to select Auto-Reassign Pending Requests on Leader Change:
When selected on the platform, whenever a Leader is subsequently changed against a requester's User Profile, this system will automatically re-assign any Approval request with a Pending status from the requester's former leader, to the newly assigned Leader.
An email will be triggered by the system to alert the new Leader of the pending approval.
(If the requester user's Leader selection is removed from their User profile's Leader field, with no other Leader added in, the workflow will stay untouched.)
Note: This option is is set at the global level and so will occur on all Workflows when enabled.