PO approval form personlization

Hi all,

I have applied some penalization on PO_APPROVAL from using WHEN-VALIDATE-RECORD so I want to override the default approval path

and use another one in some cases. i have change the value of approval path "PO_APPROVE.APPROVAL_PATH" to the needed value, but i am struggle with issue

is the the forward to, not get populated based on the selected approval path, it remains empty.

your assistance to get it done is much appreciated,

Note: I am using position based approval

Thank you