I have a problem with the double validation issue on Holiday Leaves.

Now i have userA on project management as a user, and userB is manager at project management. So, userB is the manager of userA and i can see his name on the manager section of userA.

Also i have userC as officer on Human Resources, and userD as manager on Human Resources.

I have double validation rule on leave management. When userA requests leave, userB must approve first approval, then userD (or userC, any one of this) must give the second approval for the request of userA.

However as a default in openerp, userB or userC or userD can give both approval at the same time.

Ä°s there any help to sort out this as a decsribed?

Thanks in advance.