TVs do not have a video output so you can't record from them. If you want to record from a cable box then connect the AV output of the box to the recorder AV input. The HDMI output of the cable box goes to the TV. Hopefully the HDMI and AV outputs work at the same time.
If you want to record over the air TV get a tuner with AV outputs. Split the antenna lead and connect both the TV and tuner.
Connect the AV output of the tuner to the AV input of the recorder. Connect the HDMI output of the recorder to the TV for playback only.