contract/agreement/security/res_groups.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <!-- User group -->
    <record id="group_agreement_user" model="res.groups">
        <field name="name">User</field>
        <field name="category_id" ref="agreement"/>
        <field name="implied_ids" eval="[(4, ref('base.group_user'))]"/>
    </record>

    <!-- Manager group -->
    <record id="group_agreement_manager" model="res.groups">
        <field name="name">Manager</field>
        <field name="category_id" ref="agreement"/>
        <field name="implied_ids" eval="[(4, ref('group_agreement_user'))]"/>
        <field name="users" eval="[(4, ref('base.user_root'))]"/>
    </record>

</odoo>