Open a Tab in a Container with a Button and switch tabs

The switch's script will only be executed when its value changes, not when the osc listener (the OSC{} block) receives a value, so this won't work (there's also a syntax error: missing closing parenthesis after "> 8").

You could achieve what you want by writing this int the switch's value property:

JS{{
if (OSC{/track/number/str} > 8) {
  return 2
}
}} 

or you could create a script widget with address set to /track/number/str and script to:

if (value > 8) {
  set("Bank", 2)
}