For Android 11:
1) Touch the icon at the bottom right corner of the screen, the recently used applications will be displayed.
2) If the current application supports split screen, there will be a split screen operation prompt at the top of the screen——“Swipe to corner to trigger float window/split screen” .You can follow the prompt.
Go to “Settings” -> “Button & gestures” -> “Gestures” -> “Split-screen gesture”, then in home screen or applications supporting split screen, swipe up with 3 fingers on the screen to activate split mode.
For Android 10:
1) Touch and hold the menu key while using a specific application, the recently used applications will go into split screen.
2) Touch and hold the menu key for seconds will exit split screen.