hr_payslip_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
         <record id="view_hr_payslip_form" model="ir.ui.view">
            <field name="name">hr.payslip.form</field>
            <field name="model">hr.payslip</field>
            <field name="inherit_id" ref="hr_payroll.view_hr_payslip_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='worked_days_line_ids']//field[@name='name']" position="before">
                    <field
                        name="date_from"
                        attrs="{'required': [('number_of_hours', '>', 0)]}"
                    />
                    <field
                        name="date_to"
                        attrs="{'required': [('number_of_hours', '>', 0)]}"
                    />
                </xpath>

                <xpath expr="//field[@name='worked_days_line_ids']//field[@name='number_of_hours']" position="after">
                    <field
                        name="hourly_rate"
                        attrs="{'required': [('number_of_hours', '>', 0)]}"
                    />
                    <field
                        name="rate"
                        attrs="{'required': [('number_of_hours', '>', 0)]}"
                    />
                    <field name="total"/>
                </xpath>

            </field>
        </record>
    </data>
</openerp>