How to do splitscreen on minecraft xbox?

We have the hd cable and minecraft is in hd but pressing start won't work. I'm also signed in.

You need to use an hdmi cable on a hd tv or it won't work. Use the hdmi cable instead of the red white yellow cord and plug hdmi into TV and xbox. Then press start in the game. Probably your TVs not hd and that's why it won't work