there are author and title, not series or number i.e.
and I miss to save my setting for that filter. for each import I have to change form the setting "Title - Author" to my "Author - Title"
My suggestion would be a selection from Title - Author Author - Title Author - Series ### - Title (where ### is numbering like 003)
That makes sorting more easy and you can arrange book files in directories like ...A/Asimov, Isaac/Asimov, Isaak - Foundation 03 - Alle Wege führen nach Trantor.epub
If you have the files in a database it is easy to sort by fields, If you have them on a ebook-reader you need a lot of info included in the file name to select the right one.