Approval Group escalations in Payable invoice (From PO) approval process

Summary:

When a requester submit Payable Invoice for approval, the approval goes to the entire approval group, it doesn’t matter who the requester is. If no one in the entire group approves within the time period, it is currently escalating to "NT J" (who is also in the group) as per configuration "Maximum escalation levels =1" in BPM. This is happening in all the cases, al escalations are going to "NT J".

The requirement for our organization is or desire is to have it escalate to someone NOT already in the group.

Would like to understand how the system is behaving during escalations in approval group case?