Searching your events in Google Calendar can be a tedious experience, and many people might not even remember that's an option in the Android app at all. That's likely because the search button is hidden in the hamburger menu below the different view options. It looks like Google has recognized that this position doesn't make a lot of sense, as the company is rolling out a small UI tweak that moves the search button to the top app bar.
The new position makes much more sense and should improve discoverability drastically — not everyone thinks of checking the sidebar to search for events, and even when you know where to find it, it's always a hassle to navigate to it. I can't recall many, if any, other apps that tuck away search like this.
Left: Old search button in the hamburger menu. Middle: New search button in top bar.
The search button's new position should be visible in the top bar for everyone on Android already, though you might need to download the latest version to get in on the tweak. Check the Play Store for updates or get the app from APK Mirror. Google will also roll out the UI change to the iOS app shortly.