This is my code:
<record id="module_category_vender_user" model="ir.module.category">
    <field name="name">Vender</field>
</record>

<record id="group_vender" model="res.groups">
    <field name="name">Vender</field>
    <field name="category_id" ref="website_groceries_extended.module_category_vender_user"/>
</record>

When we apply this group to internal user then we want only order menu in purchase and all other's are hide.