How would you go about creating the following graph in d3.js?

[Bernd D]

Hi Guys, I have following sample graph and I would like to ask in this group how I could achieve this with d3.js (or another graph library).

 I tried using dagre-d3 but found out that it will render it very ugly due to the edges Po1 that connect nodes in the same ranking. Because in dagre-d3 when i draw an edge between nodes of same rank then one of them will drop in rank. So now I'm back to square one thinking what to use to achieve this.

I would be very happy for some hints.