Need to create a Commercial Change Order (CCO) rule that routes the "Interim Approval" to a buyer

We have a Global Procurement department with buyers assigned to different product types (examples Buyer1 manages Electrical Components, Buyer2 manages purchase of mechanical items).

We would like to have a rule based "Interim Approval" that routes the CCO to the Buyer that manages the Purchasing Category to which the Item is assigned. There is an ability in the ChangeOrderApprovalTask to add a Category, but there are hundreds of choices for the Item Category as shown under the "Content below. How do I find the CORRECT purchasing category for the item?

Content (please ensure you mask any confidential information):

• ChangeObjectApproval
• ChangeObjectApproval.attributeCategory