Mutually; each toward the other — used when two or more parties do the same action or feel the same toward one another.
お互いに助け合ってプロジェクトを完成させた。
We helped each other and completed the project.
これからもお互いに連絡を取り合おう。
Let's keep in touch with each other from now on.
面接ではお互いに質問する時間がある。
In the interview there is time for both sides to ask questions.