Add product dimension and weight to the order CSV export

functions.php

/**
 * Add weight as line item meta in CSV export
 */
function sv_add_weight_to_csv_export_line_item( $line_item, $item, $product, $order ) {

    if ( $product->get_weight() ) {
    	$line_item['weight'] = $product->get_weight() . ' ' . get_option( 'woocommerce_weight_unit' );
    }

    if ( $product->length ) {
    	$line_item['length'] = $product->length . ' ' . get_option( 'woocommerce_dimension_unit' );
    }

    if ( $product->width ) {
    	$line_item['width']  = $product->width . ' ' . get_option( 'woocommerce_dimension_unit' );
    }

    if ( $product->height ) {
    	$line_item['height'] = $product->height . ' ' . get_option( 'woocommerce_dimension_unit' );
    }

    return $line_item;
}
add_filter( 'wc_customer_order_csv_export_order_line_item', 'sv_add_weight_to_csv_export_line_item', 10, 4 );