If you don’t want to use a plugin, there’s a really good explanation from CSS Tricks about how to convert tags from “flat” to “hierarchical”.
https://css-tricks.com/how-and-why-to-convert-wordpress-tags-from-flat-to-hierarchical/
If you don’t want to use a plugin, there’s a really good explanation from CSS Tricks about how to convert tags from “flat” to “hierarchical”.
https://css-tricks.com/how-and-why-to-convert-wordpress-tags-from-flat-to-hierarchical/