If variable value changes

Hi!

Does anyone know if there is a way to activate a trigger on change of a variable's value? There is currently an option to do this for change of clipboard contents, but don't see anything for other variables.

I am trying to create a Spotlight type process where when I type specific things into an input field that saves the value to a variable, then it will activate a specific trigger based on what the new variables value is!

Thanks!