Retain only log messages with duplicate values

Hello! I have a set of log messages with two fields, time and url.

I'd like to retain only messages with urls that are repeated in other messages.

In other words, if I were to count by url, I want only the messages that would produce counts of 2 or greater retained.

Goal here is to be able to export a csv of messages with duplicate urls only.

Is there any way to do this?