You use mutual to describe a situation, feeling, or action that is experienced, felt, or done by both of two people mentioned.
shared , reciprocal
The East and the West can work together for their mutual benefit and progress.
东西方可以为彼此共同的利益和进步而合作。
You use mutual to describe something such as an interest which two or more people share.
They do, however, share a mutual interest in design.
然而,他们确实都对设计感兴趣。