manufacture/mrp_unbuild_valuation_layer_link/views/mrp_unbuild_views.xml

<odoo>
    <record id="mrp_unbuild_form_view_inherited" model="ir.ui.view">
        <field name="name">mrp.unbuild.view.inherited - Button Valuation</field>
        <field name="model">mrp.unbuild</field>
        <field name="inherit_id" ref="mrp.mrp_unbuild_form_view" />
        <field name="groups_id" eval="[(4, ref('stock.group_stock_manager'))]" />
        <field name="arch" type="xml">
            <xpath expr="//div[@name='button_box']" position="inside">
                <button
                    string="Valuation"
                    type="object"
                    name="action_view_stock_valuation_layers"
                    class="oe_stat_button"
                    icon="fa-dollar"
                    groups="base.group_no_one"
                    attrs="{'invisible': [('state', '=', 'draft')]}"
                />
            </xpath>
        </field>
    </record>
</odoo>