vracoop_product_returnable/views/product_views.xml

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

	<record model="ir.ui.view" id="product_template_form_view">
        <field name="name">product.template.product.return.form</field>
        <field name="model">product.template</field>
        <field name="inherit_id" ref="website_sale.product_template_form_view"/>
        <field name="arch" type="xml">
            <div name="options" position="inside">
                <div>
                    <field name="is_returnable"/>
                    <label for="is_returnable"/>
                </div>
            </div>
            <field name="accessory_product_ids" position="after">
            	<field name="return_product_ids" widget="many2many_tags" attrs="{'invisible': [('is_returnable', '=', True)]}"/>
            </field>
        </field>
    </record>

</odoo>