Definition
To be so focused on the details of a situation that one fails to understand the overall picture.
He was so busy dealing with the day-to-day tasks that he couldn't see the wood for the trees and forgot the actual goal of the project.
We can't see the wood for the trees; we must consider the long-term impact of this policy on all departments.
Sometimes, she focuses too much on the details and can't see the wood for the trees, missing more important information.