flectra/addons/hr_expense/security/hr_expense_security.xml

<?xml version="1.0" encoding="utf-8"?>
<flectra>
    <record id="group_hr_expense_user" model="res.groups">
        <field name="name">Officer</field>
        <field name="category_id" ref="base.module_category_hr_expense"/>
        <field name="implied_ids" eval="[(4, ref('base.group_user'))]"/>
    </record>

    <record id="group_hr_expense_manager" model="res.groups">
        <field name="name">Manager</field>
        <field name="category_id" ref="base.module_category_hr_expense"/>
        <field name="implied_ids" eval="[(4, ref('hr_expense.group_hr_expense_user'))]"/>
        <field name="users" eval="[(4, ref('base.user_root'))]"/>
    </record>

    <record id="base.default_user" model="res.users">
        <field name="groups_id" eval="[(4,ref('hr_expense.group_hr_expense_manager'))]"/>
    </record>
</flectra>