web/web_tree_duplicate/demo/res_users_view.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!-- Copyright 2019 Onestein
     License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). -->

<odoo>
    <record id="view_users_tree" model="ir.ui.view">
        <field name="model">res.users</field>
        <field name="inherit_id" ref="base.view_users_tree"/>
        <field name="arch" type="xml">
            <xpath expr="//tree" position="attributes">
                <attribute name="duplicate">true</attribute>
            </xpath>
        </field>
    </record>
</odoo>