Hi Pedro, welcome!
Pedro, if Oliver Nelson wrote a book on harmony I don't know of it and I would be interested in getting my hands on one if he did.
Nelson's "Patterns For Improvisation" is not a harmony book, but a book of phrases for improvisation. As a matter of fact, Nelson did not include chord symbols above the phrases and there's some controversy about just how to use the book. So, not only is it not a harmony book, it's actually a bit confusing in that area.
I think mostly when folks want to learn about his harmony they study his music. There used to be (maybe it's still in print) a piano book of Nelson tunes. I think there is a transcription book of "Blues and the Abstract Truth". At any rate, you are probably going to have to google and research what music is available and then look at it, vs finding a book specifically about Nelson's harmonies.
Actually, IMO, there's no real mystery to his harmonies. His progressions are generally orthodox and it's his quartal melodic ideas and voicings of the harmonies that make his music distinct.
When did your teacher talk to Oliver? He's been dead for over 30 years. Maybe your teacher is not remembering correctly. Or maybe Oliver did write such a book and it's been long out-of-print. I would surely be interested.