I recently convert my poem site (https://aydos.net) from drupal7 to hugo.
I had node types like: poem, book, publication, translation, language, translator. And these nodes related one to another. And there exist complex fields. Since drupal2hugo (listed on tools page) does not work for me, I decided to write my own php script in which I have total control. Here what I get:
It is specific to aydos.net but I hope it will be helpful somehow.