partner-contact/partner_company_group/views/contact_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <record id="view_partner_form" model="ir.ui.view">
        <field name="name">res.partner.form</field>
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="base.view_partner_form" />
        <field name="arch" type="xml">
            <field name="vat" position="before">
                <field name="company_group_id" attrs="{'invisible': [('is_company','=', False)]}" />
            </field>
        </field>
    </record>

    <record id="view_res_partner_filter" model="ir.ui.view">
        <field name="name">res.partner.select</field>
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="base.view_res_partner_filter" />
        <field name="arch" type="xml">
            <field name="name" position="before">
                <field name="company_group_id" />
            </field>
            <filter name="group_company" position="before">
               <filter name="group_company_group" string="Company Group" context="{'group_by': 'company_group_id'}"/>
            </filter>
        </field>
    </record>
</odoo>