Thanks a lot @MichelDiz for your very clear example.
My misunderstanding came from the fact I didn’t know I can recurse on both “comments” and “author” at the same time.
Problem resolved 
Thanks a lot @MichelDiz for your very clear example.
My misunderstanding came from the fact I didn’t know I can recurse on both “comments” and “author” at the same time.
Problem resolved 