I have a sort of not-well-defined hierarchy, I guess you could say. There are certainly levels of closeness, but they are often somewhat fluid and, eh... varying in color or quality. For example, the person I would consider my closest friend right now is an ESFj. But I'm also very close, if not closer, to my sister (ENFp). But the relationship I have with each of them is different, has different qualities, different dynamics, different focusses.
The way I see it, every individual has their own connection with me (as well as all sorts of connections that in turn connect and intertwine), and each connection is unique even if there are many similarities between many of them.
If there were a visual representation of one way of looking at it, it might be something like this (probably entirely unnecessary and useless, but I felt like making it so here you go, lol):
Me being the purplish dot in the center and other people being the other dots. Each person has their own connection, but different people are different distances from me and come from different directions and interact with me in different ways. There are no real boxes or set-in-stone hierarchies. But some people are definitely closer to me than others, and that's most often based on how well I like them and how well we interact on closer levels and even how well I think they deserve it, and other variables. Nothing is ever the same for different people.
Now, despite what I say about non-well-definedness and lack of structure, I don't like lots of changes in the distances and qualities of relationships, and I don't like unexpected changes, either. Once I find a balance, I tend to like to keep it.
My natural inclination is to assume that most people are like that, having naturally and expected varying distances in their relationships, as well as showing those closeness-es in particular ways, but according to some of my experiences and conversations, apparently not?
Anyway, I have no idea if or how much this is of any use to you, Sereno.