"To make a mountain out of a molehill" is to make an unimportant matter seem important.

“把山丘夸作大山(小题大作)”就是使不重要的事情显得很重要。

youdao

Never belittle them or their interests, no matter how superficial, unimportant, or even misguided their interests may seem to you.

千万不要轻视他们或他们的兴趣，不论他们的兴趣在你看来多么肤浅、多么无足轻重或者误入歧途。

youdao

Relatively speaking, this matter is unimportant.

相对来说，这事并不重要。

youdao

My unwillingness to discuss them isn't a matter of my judgment that they're unimportant, just trying to keep at least roughly on track.

我不想讨论这些问题不是因为,我觉得它们不重要的，而是想尽量不要跑题。

耶鲁公开课 - 死亡课程节选

That applies no matter how small or unpopular or unimportant that person is and no matter how great or popular or powerful her opponent is.

CNN: Transcript: House Judiciary Committee

Seventh, surrogates of the president attempted to convince the Congress and the American people that the matter was unimportant.

CNN: Transcript: Judiciary Committee impeachment hearing