Hi,
here is the demo, https://www.e107sk.com/v2demo/magazine01/
I really don't know what you mean by top main navigation - I can't see any drop-down for news categories there.
All needed information is on that link, for example:
https://github.com/fizi/bs_magazine_01/issues - issue tab, where you can create an issue if you want the answer from the developer (Fizi), using Github issues is easier because you can post images there in Chrome directly into the text.
and on Readme files are links to Support at the bottom:
Shortly: https://www.e107sk.com/forum/fizi-e107-themes/
I can help but only because I have created that demo a long time ago, so I can test it, but nothing more.
Without problem create question here (your actual one is not clear), but if the answer is more complex, I will post it on my site and link here.
I hope, it's clear now.