newsupernova/vendor/magento/module-downloadable/etc/fieldset.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:DataObject/etc/fieldset.xsd">
    <scope id="global">
        <fieldset id="downloadable_sales_copy_order">
            <field name="entity_id">
                <aspect name="to_downloadable" targetField="order_id" />
            </field>
            <field name="increment_id">
                <aspect name="to_downloadable" targetField="order_increment_id" />
            </field>
            <field name="created_at">
                <aspect name="to_downloadable" />
            </field>
            <field name="updated_at">
                <aspect name="to_downloadable" />
            </field>
            <field name="customer_id">
                <aspect name="to_downloadable" />
            </field>
        </fieldset>
        <fieldset id="downloadable_sales_copy_order_item">
            <field name="item_id">
                <aspect name="to_downloadable" targetField="order_item_id" />
            </field>
            <field name="name">
                <aspect name="to_downloadable" targetField="product_name" />
            </field>
            <field name="sku">
                <aspect name="to_downloadable" targetField="product_sku" />
            </field>
        </fieldset>
        <fieldset id="downloadable_sales_copy_link">
            <field name="product_id">
                <aspect name="to_purchased" />
            </field>
            <field name="link_id">
                <aspect name="to_purchased" />
            </field>
            <field name="title">
                <aspect name="to_purchased" targetField="link_title" />
            </field>
            <field name="is_shareable">
                <aspect name="to_purchased" />
            </field>
            <field name="link_url">
                <aspect name="to_purchased" />
            </field>
            <field name="link_file">
                <aspect name="to_purchased" />
            </field>
            <field name="link_type">
                <aspect name="to_purchased" />
            </field>
        </fieldset>
        <fieldset id="downloadable_data">
            <field name="link_id">
                <aspect name="to_link" targetField="id"/>
            </field>
            <field name="sample_id">
                <aspect name="to_sample" targetField="id"/>
            </field>
            <field name="type">
                <aspect name="to_link" targetField="link_type"/>
                <aspect name="to_sample" targetField="sample_type"/>
            </field>
        </fieldset>
        <fieldset id="downloadable_link_sample_data">
            <field name="url">
                <aspect name="to_link_sample" targetField="sample_url"/>
            </field>
            <field name="type">
                <aspect name="to_link_sample" targetField="sample_type"/>
            </field>
        </fieldset>
    </scope>
</config>