stock-rma/rma_account/wizards/rma_add_invoice.xml

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

<odoo>

    <record id="view_rma_add_invoice" model="ir.ui.view">
        <field name="name">rma.add.invoice</field>
        <field name="model">rma_add_invoice</field>
        <field name="arch" type="xml">
            <form string="Select Invoice from customer">
                <group>
                    <field name="partner_id"
                           domain="[('customer','=',True)]"
                           string="Customer"/>
                </group>
                <separator string="Select Invoices lines to add"/>
                <field name="invoice_line_ids"
                       domain="[('invoice_id.partner_id', '=', partner_id),
                       ('invoice_id.type', '=', 'out_invoice')]">
                    <tree string="Invoice Lines">
                        <field name="invoice_id"/>
                        <field name="name"/>
                        <field name="account_id" groups="account.group_account_user"/>
                        <field name="quantity"/>
                        <field name="uom_id" groups="product.group_uom"/>
                        <field name="price_unit"/>
                        <field name="discount" groups="sale.group_discount_per_so_line"/>
                        <field name="price_subtotal"/>
                        <field name="currency_id" invisible="1"/>
                    </tree>
                </field>
                <footer>
                    <button
                            string="Confirm"
                            name="add_lines" type="object"
                            class="oe_highlight"/>
                    or
                    <button name="action_cancel"
                            string="Cancel" class="oe_link" special="cancel"/>
                </footer>
            </form>
        </field>
    </record>

    <record id="view_rma_add_invoice_supplier" model="ir.ui.view">
        <field name="name">rma.add.invoice.supplier</field>
        <field name="model">rma_add_invoice</field>
        <field name="arch" type="xml">
            <form string="Select Invoice from supplier">
                <group>
                    <field name="partner_id"
                           domain="[('supplier','=',True)]"
                           string="Supplier"/>
                </group>
                <separator string="Select Invoices lines to add"/>
                <field name="invoice_line_ids"
                       domain="[('invoice_id.partner_id', '=', partner_id),
                       ('invoice_id.type', '=', 'in_invoice')]">
                    <tree string="Invoice Lines">
                        <field name="invoice_id"/>
                        <field name="name"/>
                        <field name="account_id" groups="account.group_account_user"/>
                        <field name="quantity"/>
                        <field name="uom_id" groups="product.group_uom"/>
                        <field name="price_unit"/>
                        <field name="discount" groups="sale.group_discount_per_so_line"/>
                        <field name="price_subtotal"/>
                        <field name="currency_id" invisible="1"/>
                    </tree>
                </field>
                <footer>
                    <button
                            string="Confirm"
                            name="add_lines" type="object"
                            class="oe_highlight"/>
                    or
                    <button name="action_cancel"
                            string="Cancel" class="oe_link" special="cancel"/>
                </footer>
            </form>
        </field>
    </record>

    <record id="action_rma_add_invoice" model="ir.actions.act_window">
        <field name="name">Add Invoice</field>
        <field name="type">ir.actions.act_window</field>
        <field name="res_model">rma_add_invoice</field>
        <field name="src_model">rma.order</field>
        <field name="view_type">form</field>
        <field name="view_mode">form</field>
        <field name="target">new</field>
        <field name="view_id" ref="view_rma_add_invoice"/>
        <field name="groups_id" eval="[(4, ref('rma.group_rma_customer_user'))]"/>
    </record>

    <record id="action_rma_add_invoice_supplier" model="ir.actions.act_window">
        <field name="name">Add Invoice</field>
        <field name="type">ir.actions.act_window</field>
        <field name="res_model">rma_add_invoice</field>
        <field name="src_model">rma.order</field>
        <field name="view_type">form</field>
        <field name="view_mode">form</field>
        <field name="target">new</field>
        <field name="view_id" ref="view_rma_add_invoice_supplier"/>
        <field name="groups_id" eval="[(4, ref('rma.group_rma_supplier_user'))]"/>
    </record>

    <record id="view_rma_add_invoice_form" model="ir.ui.view">
        <field name="name">rma.order.form - invoice wizard</field>
        <field name="model">rma.order</field>
        <field name="inherit_id" ref="rma.view_rma_form"/>
        <field name="arch" type="xml">
            <xpath expr="//header" position="inside">
                <button name="%(action_rma_add_invoice)d"
                        string="Add From Invoice"
                        type="action"/>
            </xpath>
        </field>
    </record>

    <record id="view_rma_add_invoice_button_form" model="ir.ui.view">
        <field name="name">rma.order.supplier.form - invoice wizard</field>
        <field name="model">rma.order</field>
        <field name="inherit_id" ref="rma.view_rma_supplier_form"/>
        <field name="arch" type="xml">
            <xpath expr="//header" position="inside">
                <button name="%(action_rma_add_invoice_supplier)d"
                        string="Add From Invoice"
                        type="action"/>
            </xpath>
        </field>
    </record>

</odoo>