Exactly, you haven't read it. There is a lot of action on the Eastern Front. Please read it before criticising it. There is a long scene that is very heavy to stomach that details German war crimes in the Eastern Front. It doesn't explicitly happen in the Ukraine, but it stands for all that happened there. Even in a novel of that magnitude, that is pretty much all you can do.
And maybe I was wrong, maybe there are a few Ukrainian places mentioned in passing, I'm not exactly sure. But you can trust me, Follett knew what he was doing.