When the menu is open, press the View button.
While playing the game you want to record, press the Xbox button. You can change the length of recording sessions by tapping the Share button once, then going to Sharing and Broadcast Settings > Video Clip Settings > Length of Video Clip. All you need to do is double press the Share button and the recording will start. The PS4 makes recording videos extremely easy. If you’re using a console, your method of screen recording will vary depending on what console it is.