partner-contact/partner_tier_validation/data/tier_definition.xml

<odoo noupdate="1">
    <record id="partner_tier_definition_company_only" model="tier.definition">
        <field name="name">Validate New Company</field>
        <field name="model_id" ref="base.model_res_partner" />
        <field name="review_type">group</field>
        <field name="reviewer_group_id" ref="base.group_user" />
        <field name="definition_type">domain</field>
        <field name="active" eval="False" />
        <field name="definition_domain">[["is_company","=",True]]</field>
    </record>
</odoo>