partner-contact/partner_firstname/views/base_config_view.xml

<?xml version="1.0" encoding="utf-8" ?>
<!-- Copyright 2015 Antiun Ingenieria S.L. - Antonio Espinosa
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html). -->
<odoo>
    <record id="res_config_settings_view_form" model="ir.ui.view">
        <field name="name">Add partner_names_order config parameter</field>
        <field name="model">res.config.settings</field>
        <field name="inherit_id" ref="base_setup.res_config_settings_view_form" />
        <field name="arch" type="xml">
            <xpath expr="//div[@id='companies']" position='after'>
                <h2>Partner Names Order</h2>
                <div class="row mt16 o_settings_container" name="partner_names_order">
                    <div class="col-xs-12 col-md-6 o_setting_box">
                        <div class="o_setting_right_pane">
                            <field name="partner_names_order" />
                            <field name="partner_names_order_changed" invisible="1" />
                            <button
                                name="action_recalculate_partners_name"
                                string="Recalculate names"
                                icon="fa-play"
                                type="object"
                                help="Recalculate names for all partners. This process could take so much time if there are more than 10,000 active partners"
                                attrs="{'invisible': [('partner_names_order_changed', '=', False)]}"
                            />
                        </div>
                    </div>
                </div>
            </xpath>
        </field>
    </record>
</odoo>