How are option spreads and butterflies matched?

I'm looking for some informations how the exchanges manage orders in spreads or butterflies. For example let's take the CBOE and their options.
Is an order in a butterfly linked with the orderbook of the three options and how do you get a fill and how does the CBOE system manage these trades?
Unfortunately I couldn't find good informations about that topic.

Thanks and regards

Ben

 

there are a bunch of indians in IT that worry about this.. all i know is that it works