up up up! I'm looking for the same answer f^_^;;
I have my content in Framemaker 10, then I export it to HTML.
I use Sigil to convert the HTML to ePub, then I export to MOBI through Calibre.
Sigil have a tool to generate a Table of Contents and you can specify a hierarchy for each tag and it works as a makers in Kindle pretty well, But still I cannot get the "Sections & Articles" navigation menu.
Anyway I'm in the process to find the way without so much manual coding (I have to divide and export a book of 600 pages). I'll share the solution here if I can find a easy way
