Approval rules based on Purchasing Categories

Summary

Requisition approvals based on Purchasing categories

Content

Hi,

We have the below requirement.

Please guide, what is the best way to achieve this.

1. Assume there are 3 Lines in a requisition

2. Each line has different purchasing categories A, B, C.

3. For each Purchasing Category below approval groups are created 

a) Category A - Approval group A
b) Category B - Approval group B 
c) Category C - Approval group C 

4. Each Approval group is assigned to 3 users each

a) Approval group A - 3 Users assigned , One user will  approve ( First responder wins )
b) Approval group B - 3 Users assigned , One user will  approve ( First responder wins )