In this thread there's a list of useful plugboards:
https://www.mobileread.com/forums/sho...d.php?t=100949
After a lot of tests, I choose to use this scheme on the authors field:
{series}{series_index:0>2s| | - } {authors}
It'll sort the author and then the series, the results will be something like this:
Harry Potter 01 - J. K. Rowling
Harry Potter 02 - J. K. Rowling
Harry Potter 03 - J. K. Rowling
...