Before you start this glitch your going to want to have your custom game mode set up and saved ready to go.
To start this glitch your going to need a friend sat at the party screen with max party set to 2.
1. Activate your second control and start a custom game, once your game has loaded your want to join your friend by pressing options, triangle then square.
2. While you are connecting you will be kicked out of your game, you will briefly be able to select set up game. Do this with your primary control.
3. You should not be able to connect to your friend and should have a message saying "The party is not joinable" press x on both controls once to clear this.
4. You should now have the setup game menus stacked on top of your main menu.
5. Using your second controller navigate to find have and search any game mode. It helps to have someone in your party when you do this so that your not put in a game in progress.
6. As soon as you are in a lobby with other people back out your second control or you wont be able to host.
7. Wait until the intermission counts down to around 3 seconds and start netflix or spotify to suspend black ops.
8. Stay on netflix for around 40 seconds, then close app and go back to black ops.
9. After around 30 seconds everyone in the lobby should show as level 1.
10. As soon as the lobby starts counting down from 9 you need to quickly select your map and your game mode.
If it is kicking you out when you get back to bo3 and there isn't level 1s, this may be because of your internet. I have a 8mbs download and haven't been able to host every time one of my buddies has over 15mbs download they host right away. I'm not saying this is a fact but take this into consideration and test your internet before trying.