I have multiple users in same company. I want that a purchase order from one user will only be visible to the user who created it or his manager and no one else.PO must be visible for the employee in a certain department. In the employee module i have assign them departments and each user have a manager. 

I can restrict it for user only by using [('create_uid','=',user_id)] but i am unable to link it with employee. Please help and if you think that there can be another work around for this the do  share.

Thanks in advance.