WooCommerce Customer/Order CSV Export - Add additional data to exports

wc-customer-order-csv-export-modify-export-format.php

<?php

// add custom column headers
function wc_csv_export_modify_column_headers( $column_headers ) { 

	$new_headers = array(
		'lll_group'       => 'LLL Group',
		'registrant_type' => 'Registrant Type',
		'partner_spouse'  => 'Partner/Spouse',
		// add other column headers here in the format column_key => Column Name
	);

	return array_merge( $column_headers, $new_headers );
}
add_filter( 'wc_customer_order_csv_export_order_headers', 'wc_csv_export_modify_column_headers' );

// set the data for each for custom columns
function wc_csv_export_modify_row_data( $order_data, $order ) {

	$custom_data = array(
		'lll_group'       => get_post_meta( $order->id, '_lll_group', true ),
		'registrant_type' => get_post_meta( $order->id, 'Registrant Type', true ),
		'partner_spouse'  => get_post_meta( $order->id, 'Partner/Spouse', true ),
		// add other row data here in the format column_key => data
	);

	return array_merge( $order_data, $custom_data );
}
add_filter( 'wc_customer_order_csv_export_order_row', 'wc_csv_export_modify_row_data', 10, 2 );

What do we use if we want to export as Legacy? This doesn't work for that and the old code doesn't work for that.

I have the same issue as Kelowna. I'm using Legacy (one item per row), and this code doesn't appear to work for that.

This worked great, thanks. Is there a way to do this without editing the core plugin file? Perhaps a way to just add to a child theme functions.php or other sub file? :)