can't see the forest for the trees
US /kænt si ðə ˈfɔrɪst fɔr ðə triːz/
UK /kænt si ðə ˈfɔrɪst fɔr ðə triːz/

1.
木を見て森を見ず, 全体像が見えない
to be unable to understand a situation clearly because you are too involved in too many small details or problems
:
•
He's so focused on minor issues that he can't see the forest for the trees.
彼は些細な問題に集中しすぎて、木を見て森を見ずの状態だ。
•
Sometimes you need to step back and look at the bigger picture, otherwise you'll can't see the forest for the trees.
時には一歩引いて全体像を見る必要がある、さもないと木を見て森を見ずになるだろう。