pos_notes/view/pos_view.xml

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

        <record id="view_pos_orderfilter_search3" model="ir.ui.view">
            <field name="name">pos.order.filter.search3</field>
            <field name="model">pos.order</field>
            <field name="inherit_id" ref="point_of_sale.view_pos_order_filter" />
            <field name="arch" type="xml">
              <search>
                 <field name="note" string="Nota Interna"/>
                 
               </search>
            </field>
        </record>


        

    </data>
</openerp>