I'm using GoDaddy hosting, with WordPress Managed plan, so I can't edit anything in `wp-admin/` or `wp-includes/` folder, the only folder I've permission is `wp-content/`.

I tried to look it on google, and tried to find the plugins, I found this plugin `Post Filter Multiselect` but it doesn't working anymore, my WordPress version is `4.9.5` and the plugin were not updated since 9 month ago. So I tried another plugins but neither of them are working.

If I want to add this with `themes` or `plugins` how to do it? because I can't found the answer, thank you.

What I want is to make the `wp-admin/edit.php` categories filter be a multiselect, because in 1 post, there are so many categories, so to narrow it down, it need multiple categories. and there are a lot of categories, around 50 categories.