I know this is an old thread.
But, I just added this from the widget gallery.
And, I can only get it to display a list of the labels that I enter.
I don’t see how I tell it to actually display the value of the item I’ve selected.
I’m sure I just don’t grok…so, it’s probably me. 
Then you need to type in the labels to be the same as the values you push to OH when the button is pressed. This has various uses. for termostat i want to display “25 °C” on the button but you push a command to the setpoint that is is “25” only without °C
Some other use is for the ventilation when I dispay “MAX” but I push to the recuperator “7” as it has 7 preset gears that you select.