rma/crm_rma_stock_location/views/crm_claim.xml

<?xml version="1.0"?>
<openerp>
    <data>
        <record model="ir.ui.view" id="crm_claim_rma_form_view_loss">
            <field name="name">CRM - Claim product return Form</field>
            <field name="model">crm.claim</field>
            <field name="inherit_id" ref="crm_claim_rma.crm_claim_rma_form_view"/>
            <field name="arch" type="xml">
                <xpath expr="//button[@string='New Delivery']" position="after">
                    <button name="%(action_claim_picking_loss)d"
                                    string="New Product Loss"
                                    type="action" target="new"
                                    context="{'warehouse_id': warehouse_id,
                                        'partner_id': partner_id}"/>
                </xpath>
            </field>
        </record>
    </data>
</openerp>