Satellite Signal Mirroring

We have Winnebago View with Dish Network. One receiver-two TVs. The front TV is connected to the receiver via HDMI. Works great. How can I get the rear TV to view the same as the front. The HDMI input choice on the rear TV gives no picture.

I called Dish Network. They said there is something called mirroring using a splitter. How can this be connected to generate a sat receiver out signal for the rear. The Receiver is RF remote so channel changes can be made from the rear of the camper.

thanks for any help.