if u are trying to add xpath constraint in entity level do this:
You would have created 1 association which maps your entity with account entity . you can use that associaton to retrieve the objects created by current user.
Consider your entity is Project and conside your have association with account entity as Project_Account .
[Project.Project_Account = $currentUser]
The above xpath condition will give current user objects.
i think you want to store owner who created the object. is it correct?
if yes, you can use domain model default option-
I want to show al the windows who are submitted by the currentuser. Everytime the app is initiated i create a person.
Adding to the above answer, You could also add on a page level in datagrid or List xpath [System.owner = '[%CurrentUser%]'] to show the records related to the owner.