pos/pos_order_return/wizard/pos_partial_return_wizard_view.xml

<?xml version="1.0"?>
<!-- Copyright 2016-2018 Sylvain LE GAL (https://twitter.com/legalsylvain)
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).-->

<odoo>

    <record id="view_partial_return_wizard_form" model="ir.ui.view">
        <field name="model">pos.partial.return.wizard</field>
        <field name="arch" type="xml">
            <form string="Partial Return">
                <group string="Lines to Return">
                    <field name="line_ids" nolabel="1">
                        <tree editable="bottom">
                            <field name="pos_order_line_id" force_save="1"/>
                            <field name="initial_qty"/>
                            <field name="max_returnable_qty"/>
                            <field name="qty"/>
                        </tree>
                    </field>
                </group>
                <footer>
                    <button string="Confirm" name="confirm" type="object" class="btn-primary"/>
                    <button string="Cancel" special="cancel" class="btn-default"/>
                </footer>
            </form>
        </field>
    </record>

</odoo>