Referencing editors and authors in one list

Hi there,

I’m working with JabRef and LibreOffice and got stuck with setting up the export for the references list in LO. I want books to be listed alphabetically according to author- OR editor-field. In JabRef I’ve added books with content only in one of these two fields. Here is what I’ve tried so far:

This code provided an alphabetic list of authors followed by an alphabetic list of editors:

To merge this lists together, I’ve tried the following which obviously did result in an empty LO references list:

How do I need to change my code to get authors and editors listed alphabetically together?

Thanks in advance for your help.