I am working on complex PO in service procurement , i am trying to enter pay item owner in order to be used for work confirmation approvals , when I select an employee from the list nothing is populated in owner filed.
You are not giving us any information on what you have done so far, only that the result is not what you want.
So, what did you do exactly? What is the relation between your list item and owner field? If these are two different items on your page, you probably need to add an On Change dynamic action to the list item.