In this company, employees are divided into there different ranks depending on the role they are expected to take.
Employees are divided into three job-ranks depending on expected roles. は間違いませんがもっとはっきり言いたいと
In this company, employees are divided into three different ranks depending on the role they are expected to take.
In this company「当社で」はなくてもいけます。
employees are divided into three different ranks「社員は3つの等級に区分される」は "different" がある方は良いです。"job-rank" はあまり言われていないとおもいますが "rank" だけがあればいけます。
「期待される役割に応じ」に "depending on the role they are expected to take" の方が良いです。"expected role" と言えば「期待する役割」になってしまいます。