Or, we could say, that it applies to architecture of much more than buildings. For example, how do we architect working environments, group synergy, cyberspace meeting spaces, and much more. This applies to whole systems in the sense that a system will behave differently depending on how it has been arranged, depending on how key functions have been placed in relation to each other, and on how people flow through the system. That allows people to choose a place for their interactions that carries a particular meaning to them and a particular degree of intimacy. If there is no gradient, and everything just flows together, certain types of interaction are not likely to take place, or they are awkward.
People work best in relatively small groups.
However, they also get stimulation from interaction with wider groups of people. So, working environments that group 2-8 people at a time together fairly closely, but that also provide visibility of other groups, and provide space for more random interactions, will be most productive. The common meeting spaces would need to be quite centrally placed, but on the path in or out of the environment, not out of the way.