Tap 
Menu > 
Playback.
Start Playback
- Tap
in the window (or 
in the screen’s upper-right corner). - Set the start time and then tap OK.
- Choose a playback type.
- Select camera(s).
- Tap Start Playback.
Split Recording Playback
- Tap a window.
- Tap
to split the video playing in the window. - Tap a window and then tap
to play.