There are moments when you need to add content behind the order line items in your woocommerce admin. In my case for example I needed this to show a reference id stored under a product.
You can get the product id from the $item->get_data(); array.
/**
* Adds content after order item meta
*/
function th_add_content_after_order_itemmeta( $item_id, $item, $product ) {
$item_data = $item->get_data();
$product_id = $item['product_id']; // If you need to do something with the data from the product..
echo 'Content after order itemmeta';
}
add_action( 'woocommerce_after_order_itemmeta', 'th_add_content_after_order_itemmeta', 10, 3 );