oca-technical/odoo-bringout-oca-crm-crm_location/crm_location/views/crm_lead_view.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <record id="crm_lead_view_form" model="ir.ui.view">
        <field name="name">Add city completion helper field</field>
        <field name="model">crm.lead</field>
        <field name="inherit_id" ref="crm.crm_lead_view_form" />
        <field name="arch" type="xml">
            <xpath expr="//group/group[1]/div/field[@name='city']" position="before">
                <field
                    name="location_id"
                    options="{'create_name_field': 'city'}"
                    colspan="4"
                    placeholder="City completion"
                />
            </xpath>
            <xpath
                expr="//notebook/page[@name='lead']/group/group[1]/div/field[@name='city']"
                position="before"
            >
                <field
                    name="location_id"
                    options="{'create_name_field': 'city'}"
                    colspan="4"
                    placeholder="City completion"
                />
            </xpath>
        </field>
    </record>
</odoo>