Welcome to the forums @Gailmccarthy
HDMI switches should be pretty straight forward. You should have a few inputs and an output. You would plug the hdmi cables from the devices into the inputs of the hdmi switch, then have an hdmi cable from the output slot of the hdmi switch to your TV. Did you try this out? Not an expert when it comes to HDMI switches but maybe our residents experts may able to provide you with some more information.
@RogersShaun should be plug and play right?
I'm confused about your post. Is your goal to connect all your output devices to your TV? If so, the TV has to be the output device and your Nextbox, PS3 etc. are input devices to the HDMI switch.
I agree with jimboden. I don't know why the OP needs an HDMI unless he has more devices than his TV has HDMI inputs. The NB3 HDMI is an output and goes to one of the TVs HDMI inputs. Same for the other devices. If there are more devices and no more TV inputs, then you's use a switch as suggested in the first and second replies.
Well i would think the most common use for HDMI switches is for when someone has more devices than hdmi inputs on thier tv. Im guessing the OP is in this situation.
Also @Gailmccarthy your steps sound wrong
Nextbox output to HDMI switch input
PS3 output to HDMI switch input
Xbox output to HDMI switch input
Wii U output to HDMI switch input
Finally - HDMI switch ouput to TV HDMI Input
Did you end up getting it working?
If the TV has more than 1 HDMI input, I would suggest using one of them as a dedicated Nextbox input. I have an 8 years old Panasonic TV with only 2 HDMI inputs and I recently got a Monoprice 4 input HDMI switch. I have my Nextbox in 1 dedicated HDMI input on the TV and the HDMI switch output into the other HDMI input on the TV . I have a Blu-Ray player, an Xbox and a Chromecast stick into 3 of the switch's inputs. It works very well. Since the majority of time I am using the Nextbox to watch TV, I don't want the trouble of switching the HDMI switch on/off and input number each time.