partner-contact/partner_contact_birthdate/views/res_partner.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
     © 2015 Grupo ESOC Ingeniería de Servicios, S.L.U. -->

<flectra>
    <record id="view_personal_information_birthdate_date" model="ir.ui.view">
        <field name="name">Birthdate Date field</field>
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="base.view_partner_form"/>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='function']" position="after">
                <field name="birthdate_date" attrs="{'invisible': [('is_company', '=', True)]}"/>
            </xpath>
        </field>
    </record>
</flectra>