Hi,

Please try using below code

<record id="employee_inherited_basic_form_view" model="ir.ui.view">
<field name="name">hr.employee.form.inherit.employee.basic</field>
<field name="model">hr.employee</field>
<field name="inherit_id" ref="hr.employee_inherited_basic_form_view"/>
        <field name="arch" type="xml">
<xpath expr="//field[@name='custom_field']" position="attributes">
                <attribute name="readonly">1</attribute>

                <attribute name="groups">base.group_user</attribute>
            </xpath>
        </field>
    </record>

In this we need to add the module name of the reference record in ref

Hope it helps