Patrick Aha, you want bunq to implement this. I don't think that'll happen soon. Bunq doesn't even have this for themselves. You can't make a rule to transfer money from account Salary to account Groceries when a large sum arrives or whatever. Let alone that this is possible when that happens on accounts at another bank.
Your best bet is to find a Service Provider that will make this rule system and also connects to both bunq and Rabobank. I don't think those actually exist now.