How Does the 'Involved Parties' in 'Buy Shipment' gets populated?

In the buy shipments under 'Involved Parties' how does the 'Involved Party Contact' with 'Involved Party Qualifier' of 'Planner' and 'Logistics' gets populated?

I have checked and there are no 'Automation Agents' or 'Auto Assignment Rule' for this.

I have also checked the associated 'Corporation id' but still no use.
Can anyone please help me out on this?