You're simply not going to get a great deal of meaningful formal philosophy from that mess, try as you might to find influences. Schopenhauer, certainly, and more than a little of Hegel and Marx as the author cites, but no real firm grasp of any of them. Citing one's focus of hostility - in his case the Jews - as being contrary to nature is not, IMHO, a precocious case of eco-madness but a habit that goes back at least to Rousseau. What drove Hitler was hatred, passion, and paranoia, not philosophy.
Precisely - passion, willpower and instinct, rather than reason, is at the heart of the German existentialist movement, which was formalized by the likes of Schopenhauer and Nietzsche - Hitler’s 2 favorite philosophers - and Hitler read a lot more books than most people read today. Sadly, many in the West have invested deeply in Germany’s godless intellectual traditions of the 1800’s and early 1900’s and are quick to portray Hitler as a blithering idiot akin to a Hogan’s Heroes TV show - but this is nonsense. I would encourage to watch this by Dr. Stephen Hicks based on his book “Nietzche and the Nazis” - https://www.youtube.com/watch?v=O-WaeXHMeho.
Here is more on the same subject - https://www.youtube.com/watch?v=jOt2KhpCatg.
Fascist expert Georg Lukacs pointed out that tracing the roots of Fascism includes virtually every critical German philosopher of the 1800’s including, but not limited to, Schopenhauer, Nietzsche, Dilthy, Heidegger, and even Jaspers. Carl Gustav Jung was no fascist slouch either, but gets out of it because he is Swiss. Heidegger, the most influential philosopher (again existentialism) of the 20th century, was also a flaming Nazi early on. Worse, all these men are still extolled in modern academia by the Left, and their ideas are very pervasive.