If you have a lot of categories (like I have on geargrabber.net) you may find that scrolling and finding the category you are looking for is time-consuming. Here’s what the default WooCommerce category metabox looks like on a Product Set “edit” page:
List of long categories in WooCommerce.
You can use the Post Category Filter plugin to add a filter to your WooCommerce category box to make it easy to filter your long list of WooCommerce categories to something more manageable.
Here’s what the end result looks like:
WooCommerce categories with search filter.
Simple as that!