zyend

and yet you give it a 5 star?

The way I did it with is ACF and then hide the old stuff we don’t use, without touching the plugins.

It should be fine, however, Recommend you move that function to theme > functions.php, so future plugin patch won’t erase it.

Thanks after final changes, the code to grab subcategory of a post as follows:

foreach((get_the_category($post->ID)) as $category) {
	if ($category->category_parent == 4 ) {
		$subcat=$category->cat_ID;
	}
};

Thank you!