You could make use of WordPress' get_term_children() function on the save_post hook. A nice thing about this is that get_term_children() is recursive and collapses to a single dimensional array, so if you were to ever add smaller subdivisions as a third, fourth, fifth level, etc - you will … Read more about Stack Overflow Answer: 60079535

This following an example of the shortcode: [ xyz-ips-link ] Here is the HTML output of that shortcode: Link to Original WPSE Question … Read more about SO – 52655773 Example

This is a before the shortcode: [round_time_to_next_15_min_interval] :This is after. Timer Div Link to Original WPSE Question … Read more about WPSE – 314147 Example