An AC unit sits on the roof. Once it comes into the coach it can have one of two assemblies mounted on it. Ducted (controlled by a thermostat on wall) and a non-ducted (which all the controls on the unit as you see it). Depending on the size of your rig the bedroom unit may be the same size as the Living room unit or a little smaller.
I'd pop the inside cover off and there will be a foam dust screen that I would wash or change. Look up in the unit and if the coil in there is dirty you can gently vacuum it. Under the cover on the roof the cooling coils may be dirty and require cleaning. If everything is clean then it maybe low on charge meaning there is a leak.
If you can find a matching unit you can probably get by with only replacing the roof unit and not have to replace the internal portion.