I think you're going to have to be a bit more descriptive, here. You mean the Bell box only has one input?
We had 2 TVs and 1 cable line. The cable company dudes came and installed another box downstairs for that TV. It was running on the same cable line, but the box allowed you to have separate channels on each TV.
So, I suspect that each TV needs its own box, otherwise the best you could hope for is for each TV to show the same channel. Change on one, it changes on the other. You probably don't want that. So, I would call my trusty Bell rep on the phone and tell them what you want. They may charge you a deposit for the box, but you should get it back when you cancel your account. The service "should" be free.