Why do we mostly only hear of eastern or Greek philosophers? What about ancient Roman philosophy? Or ancient Norwegian philosophy? Or even ancient Egyptian philosophy? I don't recall any philosophers of any of those ancient civilizations except for a Marcus guy from Rome who I obviously don't find interesting enough to remember his name.
philosophy is a world wide phenomenon. if you're thinking about philosophy as an academic subject, purely for research purposes, then that's quite recent, possibly around when the universities started to gain in prominence. but if you're thinking about philosophy as thinking about the Big Things in life, then it's everywhere.
i'm surprised you say that you don't hear of ancient roman philosophers because i've always thought that they were quite famous. lucretius was an epicurean, who wrote the work de rerum natura 'on the nature of the universe' and seneca was a stoic who wrote a lot of interesting works. they're really the tip of the ice berg.
ancient egyptian philosophy was most def a thing, but it's less well known unfortunately, because frankly there isn't a lot of people who can read ancient egyptian and who do a lot of research on it. and not much of a market, aside from the academia, who read it.
if you're interested you should definitely research for yourself. i've read two books recently about aztec philosophy and maori philosophy, both super interesting.