app-odoo/app_event_superbar/views/event_event_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <!-- Search -->
    <record id="app_event_event_search_superbar" model="ir.ui.view">
        <field name="name">app.event.event.search.superbar</field>
        <field name="model">event.event</field>
        <field name="inherit_id" ref="event.view_event_search"/>
        <field name="arch" type="xml">
            <xpath expr="//search" position="inside">
                <searchpanel view_types="list,kanban,pivot,graph,calendar">
                    <field name="stage_id" enable_counters="1" select="multi"/>
                    <field name="date_begin"/>
                </searchpanel>
            </xpath>
        </field>
    </record>
</odoo>