need alternate approach for Exclusive gate way conditions

Summary:

We have a three level approval workflow where Second level approver will select the third level approval ,means third level approval is optional.

case 1 - if second level approver select the third level approver name and approved the transaction it will go for third level approval.

case 2- if second level approves the transaction with out the third level then the transaction is approved.

case 3- if second level Rejects the transaction with out the third level then the transaction is Rejected.

the issue is if second level selects the third level and rejects the transaction still it is going to the approval for third level. below i have attached the file with detailed .