I use a custom column call sserie for serial name like Tamora Pierce Circle series.
01 Circle of Magic : 4 books
02 The Circle Opens : 4 books
03 Circle Continues : 2 books
04 The Circle Reforged : 1 book so far
And sort them all over Calibre and my ebook reader aren't easy.
Her is my setup:
Ereader : {author}/{#sserie:0>2d|| - }{series}/{series_index:0>2d|| - }{title}
Metadata plugboards : Format:epub Enhed:"Your ereader" Kildeskabelon:{series_index:0>2d|| - }{title}
Save books on disk : {authors}/{#sserie:0>2d|| - }{series}/{series_index:0>2d|| - }{title}
Tweaks sort_columns_at_startup = [('authors', 0), ('#sserie', 0), ('series', 0)]
Hop it'll help.