How create a chain reaction?

ozonostudio

im making a game with chain reaction, but i don't know how do it, the deal is: you click one time any actor for select him, and click another, and another, and another, and when you tap for second time any of the selected actors all the selected actors are destroyed, but i don't know how destroy in chain, i can make all the rest, double tap; destroy on the second tap, but i can make a chain reaction