Approval Rule based on person number or assignment number

Hello All,

Need assistance to get the approval rule based on person number or assignment number for expense report submitted. We have requirement where one person doesn't have manager when he submits the expense report it should trigger one approval group. We have built approval rules based on Cost Center and he is one of the Cost Center approve. We enabled Prohibit self approval and reassign to his manager.

Thanks & Regards,

Srikanth