web/web_disable_export_group/templates/assets.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2016 Onestein
     License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl).-->
<odoo>
    <template id="assets_backend" name="web_disable_export_group assets" inherit_id="web.assets_backend">
        <xpath expr="." position="inside">
            <script type="text/javascript" src="/web_disable_export_group/static/src/js/disable_export_group.js"></script>
        </xpath>
    </template>

</odoo>