Hello Fiona92,
Theoretically what you ask for can be done with the help of custom CSS, but what would you like to achieve? The filter items search box is useless by itself: it doesn’t apply filters and is only there to help in searching through the long lists of options.
In the particular case of ISBN, I would like to warn you against using this product feature as filter. If I understand it well, ISBN is unique for each product, which means that you can potentially have thousands of ISBN records. This amount of filtering options will become a severe hit on your server resources and page load times.
Hello and thank you.
I will take your advice and not use the search feature for ISBN.
I have ISBN set as a custom field and will look for a search plugin to use rather use that then.
Thank you
