zero in

To focus one's aim; to zoom in and center (on something).

“The pilot zeroed in on the bunker and launched a guided missile.”

To successfully narrow down a search (for).

“See if you can zero in on the caller.”

To concentrate or focus one's attention (on a task).

“One member of the check fraud team will zero in on the fingerprints.”

To converge (on).

“At the spring sale, everyone zeroed in on the bargain clothes.”