Track WordPress Site Search with Google Analytics
Login to Google Analytics and go to the Admin button. Find your property and select the view you want to edit.
Click on the view settings link for that property. One that page is loaded, scroll down and find the site search area. If the slider is clicked to off, click on. Here’s what that looks like:
Once clicked on, you see some additional menu items appear. They look like this:
For WordPress, all you need to enter is the letter s in the box.
Let Google Analytics collect data for a few days, and you should start to see your results.