hr_simplify_view.xml

<?xml version="1.0" encoding="UTF-8"?>

<openerp>
    <data>

        <record id="view_contract_form" model="ir.ui.view">
            <field name="name">hr.contract.form.inherit</field>
            <field name="model">hr.contract</field>
            <field name="inherit_id" ref="hr_contract.hr_contract_view_form"/>
            <field name="arch" type="xml">
                <data>
                    <field name="employee_id" position="replace">
                        <field name="employee_id" required="1" on_change="onchange_employee_id(employee_id)"/>
                    </field>
                    <field name="job_id" position="replace">
                        <field name="employee_dept_id" invisible="1"/>
                        <field name="job_id" required="1" domain="[('department_id', '=', employee_dept_id)]"/>
                    </field>
                </data>
            </field>
        </record>

    </data>
</openerp>