[Horus68]

Using the tip from @DNSB I was able to "save to disk" a pdf file using only the first author for the file and folder names:

My save to disk tempalte:

{author_sort:sublist(0,1,&)}/{author_sort:sublist(0,1,&)}{title:.60| - |}/{author_sort:sublist(0,1,&)}{series:.25| - |}{series_index:| - |}{title:.55| - |}

The file and folder structure output is:

Doe, John\Doe, John - My own history\Doe, John - My collection - 1 - My own history.pdf

Note:
I can't use in this template, to always saves the series number with 2 number format, the code

{series_index:0>2s| - |}

I can only use

{series_index:| - |}

The series code for numers as "01, 02, 03) instead of 1,2,3 works fine in the template if I don't use the sublist code

{author_sort:sublist(0,1,&)}

more than once in the template code.
But I can live with that!