How to make a menu like on yandex.market?

Question

css

Yandex market has a catalog menu
https://skr.sh/s8hE1Yqu6eM
if in the left block (where there are categories) move the mouse diagonally over it from the upper left corner to the lower right from the first item to the others, then in the right block of the subcategory are not shown, i.e. hover does not work, and if from the top right diagonally down to the bottom left, t work.
How can this effect be reproduced?

Answer 1

I immediately remembered this article from 2013, it's about amazon, but the meaning is the same =)