I used to have a separate doc file for each chapter. Maybe I got into that habit because of posting stories on sites like SOL where you post chapters individually.
I carried that technique over to my novels — until now!
You can input a docx file into Calibre and, if you use Word's "Heading 1" formatting for chapters, it will automatically create the TOC. So I merged my individual chapter files into one big docx file.
What I didn't know is that when you do that, Word lists the chapter names to the left (like a TOC) and, when you click on a chapter name it takes you to the beginning of that chapter. I love it.
So even if I'm writing a multi-chapter story to post on SOL, I'll now write it as one file and break it up into separate files when I post it.
I don't know if LibreOffice has this capability, but for you Word users it's great.