Don't split hairs. You know what I'm getting at.

不要钻牛角尖。你知道我是什么意思。

I don't mean to split hairs.

我不是想吹毛求疵。

Why split hairs over the color of the dress?

干吗对连衣裙的颜色吹毛求疵呢？

You really don't need to split hairs on this issue.

对于这件事，你实在不必过分细心。

I don't want to split hairs over such small matters.

我不想在这些小事上吹毛求疵。