Hi SGrant,
The Approval List workspace in the Reference section is design for Admin/Selected User to specify certain approvers and group them accordingly.
This is use to help control and monitor the approvers that is able to approve the workflow in various workspaces.
It is design to help minimize errors when selecting approvers, and preset the approvers based on their roles.
Go to the Change Order WS under Engineering. You will see in Section 3 - Approvals you can see the setup and use of Approval Lists.
The approval lists we pull the names that have been pre-selected to move a transition in the workflow.
I hope this helps answer your question.
Thanks,
Trung

Trung Nguyen | PLM Product Management | Autodesk, Inc.