Clever people, I've tried so many times to reconstruct this offset path effect in Illustrator but failed big.

I can't get it mathematically or optically to work.
I'm both interested to know how to achieve the offset part and how to create the overlapping parts as well.

I'm using Illustrator CC.

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/kapna.png