“东方国家的”可以翻译为“of Eastern countries” 或者 “from Eastern nations” (具体使用可根据语境调整)。
例如:
The cultural traditions of Eastern countries are rich and diverse.(东方国家的文化传统丰富多样。)
Customs from Eastern nations often fascinate Western tourists.(东方国家的习俗常常让西方游客着迷。 )