So, let 's suppose I registered a taxonomy 'hierarchical keywords', for the attachment screen, in fact the same type as "categories".
I populated it with the keywords of my pictures throughout the iptc properties. And, as the keywords are not hierarchical in the iptc, I rebuild by hand the hierarchy I have in Lightroom ( from Adobe).
So now I 'd like to use them on my website, but if I use the wp function wp_get_object_terms( $attachment_id, 'hierarchical-keywords' ), I have a simple list of them, without the hierarchy. But, in the objects, if I look at "parent", I have different values with most of them equal to zero. So the hierarchy is there.
So my question, is there a wp function to display on the front-end these keywords as I have them in the back-end?