I'd like 4 levels of hierarchy in my Kindle navigational TOC (aka "logical TOC" in Kindle Publishing Guidelines terminology), but when I do this:
1. InDesign CC → File → Export → (choose my nested TOC)
2. `KindleGen in.epub -o out.azw`
the "Kindle for PC" software only shows the first level of headings, effectively flattening out levels 2, 3, and 4. However, I know Kindle for PC can show at least 3 levels, as I see in another Kindle book in my library.
Interestingly, if I click Kindle Previewer → View → NCX View, I see the nesting properly. Do I need Indesign 6 with the Kindle Export for InDesign CS6?