oca-technical/odoo-bringout-oca-hr-hr_employee_lastnames/hr_employee_lastnames/views/hr_views.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <record id="view_employee_form_inherit" model="ir.ui.view">
        <field name="name">hr.employee.form.firstname.inherit</field>
        <field name="model">hr.employee</field>
        <field name="inherit_id" ref="hr_employee_firstname.view_employee_form" />
        <field name="arch" type="xml">
            <data>
                <xpath expr="//field[@name='lastname']" position="after">
                    <field name="lastname2" />
                </xpath>
            </data>
        </field>
    </record>
</odoo>