pos/pos_place/security/res_groups.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (C) 2015 - Today: GRAP (http://www.grap.coop)
@author: Sylvain LE GAL (https://twitter.com/legalsylvain)
License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->
<odoo>

    <record id="group_pos_place_user" model="res.groups">
        <field name="name">User</field>
        <field name="category_id" ref="module_category_pos_place"/>
    </record>

    <record id="group_pos_place_manager" model="res.groups">
        <field name="name">Manager</field>
        <field name="category_id" ref="module_category_pos_place"/>
        <field name="implied_ids" eval="[(4, ref('group_pos_place_user'))]"/>
    </record>

</odoo>