No such thing as selflessness

In Chapter Two Book I of Aristotle's Ethics there is a line that basically says that achieving "the good" for a people people (or city) is greater or more divine than it is for an individual. First, I don't see how if the individual and the cities goods are the same that the cities could be greater. The city is just a collection of indivuals trying to pursue their goals that will allow them happiness. The only logical way I can see the happiness of a city as greater is that if the result of the individual's work that is happiness did not depend on doing the work. This conclusion is based on the assumption that the reason people derive happiness from work is from the satisfaction they get from doing it. I would argue that all of the work and happiness is based on selfish sastisfaction. Even self-sacrifice is a form of selfishness in that it is done in the name of the things that the sacrificer holds important. These efforts may be beneficial to the community but on a deeper level all actions are selfish because individuals derive happiness from them. Therefore, the communities happiness may seem more divine or greater only because the structure of a community allows for individuals to accomplish their selfish little goals. I see how the idea of greater community seems appealing however it is an illusion and should be viewed for what it really is, a collection of selfish people at opposition with one another.