stock-rma/rma_account/wizards/rma_refund.xml

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

        <record id="view_rma_refund" model="ir.ui.view">
            <field name="name">rma.refund.form</field>
            <field name="model">rma.refund</field>
            <field name="arch" type="xml">
                <form string="Credit Note">
                    <group>
                         <group>
                             <field name="description"/>
                         </group>
                         <group>
                             <field name="date_invoice"/>
                             <field name="date" groups="base.group_no_one"/>
                         </group>
                    </group>
                    <field name="item_ids">
                        <tree string="RMA Lines" editable="bottom">
                            <field name="rma_id"/>
                            <field name="product_id"/>
                            <field name="name"/>
                            <field name="product_qty"/>
                            <field name="uom_id" groups="product.group_uom"/>
                            <field name="qty_to_refund" readonly="0"/>
                        </tree>
                    </field>
                    <footer>
                        <button string='Create Refund' name="invoice_refund" type="object" class="btn-primary"/>
                        <button string="Cancel" class="btn-default" special="cancel"/>
                    </footer>
               </form>
            </field>
        </record>

        <record id="action_rma_refund" model="ir.actions.act_window">
            <field name="name">Create Refund</field>
            <field name="res_model">rma.refund</field>
            <field name="view_type">form</field>
            <field name="view_mode">tree,form</field>
            <field name="view_id" ref="view_rma_refund"/>
            <field name="groups_id"
                   eval="[(4, ref('account.group_account_invoice'))]"/>
            <field name="target">new</field>
        </record>

        <record id="view_rma_line_button_refund_form" model="ir.ui.view">
            <field name="name">rma.order.line.form</field>
            <field name="model">rma.order.line</field>
            <field name="inherit_id" ref="rma.view_rma_line_form"/>
            <field name="arch" type="xml">
                <xpath expr="//header" position="inside">
                    <button name="%(action_rma_refund)d" states="approved"
                            string="Create Refund" class="oe_highlight"
                            type="action"/>
                </xpath>
            </field>
        </record>

        <record id="view_rma_line_supplier_button_refund_form" model="ir.ui.view">
            <field name="name">rma.order.line.supplier.form</field>
            <field name="model">rma.order.line</field>
            <field name="inherit_id" ref="rma.view_rma_line_supplier_button_form"/>
            <field name="arch" type="xml">
                <xpath expr="//header" position="inside">
                    <button name="%(action_rma_refund)d" states="approved"
                            string="Create Refund" class="oe_highlight"
                            type="action"/>
                </xpath>
            </field>
    </record>

    <record model="ir.values" id="values_action_rma_refund">
        <field name="model_id" ref="model_rma_order_line"/>
        <field name="name">Create Refund</field>
        <field name="key2">client_action_multi</field>
        <field name="value"
               eval="'ir.actions.act_window,' + str(ref('action_rma_refund'))" />
        <field name="key">action</field>
        <field name="model">rma.order.line</field>
    </record>

    </data>
</openerp>