WordPress – Print Post Taxonomy Terms in Hierarchical Order

Let's say we have a post with following hierarchical categories:
Parent
- child
-- sub-child

And we want to print / display these categories on single post page in same hierarchical order, like:

Parent, child, sub-child

Use below code in single.php where you want to print the taxonomy terms in hierarchical order.

<?php
$taxonomy = 'category'; // change this to your custom taxonomy name.
$terms = wp_get_post_terms( $post->ID, $taxonomy, array( "fields" => "ids" ) );
if( $terms ) {
  $terms = trim( implode( ',', (array) $terms ), ' ,' );
  wp_list_categories( 'title_li=&taxonomy=' . $taxonomy . '&include=' . $terms . '&separator=, &style=' );
}
?>

In above code, on line 2, change the value of $taxonomy to your custom taxonomy name if you wish to use this code for custom taxonomy terms.

Display customisation

Please refer to WordPress function wp_list_categories to customise the display of taxonomy terms.