My understanding of what this means is to think of myself as the lowest in the hierarchy of the group and to try to put everyone else’s needs above my own. The only way I can do this however is if there’s something in it for me because that is my nature. In other words, in order to act altruistically I must do it it the only way I’m capable of doing it, for my own ego.
I can’t think of an action that does not follow the law of maximum benefit. Even self sacrificing acts are done based on a calculation of perceived benefit. For example, a soldier who sacrifices himself for his unit is still making that decision based on a perceived benefit from doing so.