I still don't understand what it is you want to do.
What is the goal you are after? which events do you need form which objects?
If you want to filter the button events, you can install an event filter on the buttons.
This all seems very over engineered and complex for no reason.
Also, do you really need to fileter event by another object?
Are you aware you can process events in the objects themselves by overloading event() or specialized event handler?

In short: please explain what is your goal - not what you want to do (like filtering some event) - depending on the goal we can see what is the best method to achieve it.