I am not sure I understand 100% of your question but, I think you need to send the playback intensity value to the kiosc.
To do that, you will first have to ask the CueCore to send the playback value via OSc or UDP/TCP. In show control create a playback action.
Select intensity as trigger type, and change as trigger flank, and do not forget to select which playback you want teh value from.
Then create a UDP/OSc/TCP task that will send a float as it is a percentage.
On the KIOSC side, your fader already have a tag to be able to control the intensity of playback, if you send a float value via UDP/OSC to this tag to teh Kiosc then you will control the fader in the Kiosc.
Do not forget to change the Fader to float between 0.0 and 1.0 in Kiosc editor.
I hope this will help you,