Maybe you have many categories. This extension can filter and sort product by categories.
1. Sort categories by name;
2. Filteres categories.
No Installation and core modification required, just upload the xml file in package to vqmod/xml directory.
Thanks for using this.
If you have same error or nothing show, don't forget, this just MOD, which maybe don't work correctly with another modifications.
I recommended use fully extension which you see below.
Admin product filter
Gift the developer 1$