rma/crm_rma_stock_location/views/crm_claim.xml

<?xml version="1.0"?>
<odoo>
    <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">
            <button name="%(crm_claim_rma.action_claim_picking_in)d" 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}"/>
            </button>
        </field>
    </record>
</odoo>