I’m bad at searching the web.
Someone please find me the web pages of the Greek texts of the commentaries on Aristotle’s “On the Soul (peri psyche^s) Book 3 (triton) Chapter 8 (or, e^ta)” by the following ancient commentators.
John philoponus
pseudo Simplicius
Olympiodorus
I don’t think Olympiodorus wrote a commentary on Aristotle’s De Anima. At least
not according to Wikipedia, and there isn’t one in the TLG.
There’s this book, Commentaria in Aristotelem Graeca, but it’s very difficult to search
and find the relevant commentator, and even more so the relevant chapter in which you’re interested.
I’ve made PDF documents of the relevant chapter in each commentary from the TLG database.
(I don’t own this database but I wish it would have been free to browse to everyone. No one should
charge people for access to this massive and invaluable corpus.)
Commentary on Aristotle’s De Anima - Simplicius (spurious) - Book 3 Ch.8
Commentary on Aristotle’s De Anima - Joannes Philoponus - Book 3 Ch.8
How kind you are ! Thank you ! 
I found Archive.org. seems to have the texts too. If you don’t know of the site, please try it.