partner-contact/partner_multi_relation_tabs/demo/res_partner_relation_demo.xml

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

    <!-- Relations -->
    <record id="relation_company_ceo" model="res.partner.relation">
        <field name="left_partner_id" ref="partner_big_company" />
        <field name="right_partner_id" ref="partner_important_person" />
        <field name="type_id" ref="relation_type_company_has_ceo" />
    </record>

</odoo>