主语是the type of relations (prevalent within a primary group) ,括号里面是主语的后置定语.
谓语是exist.
前面都是状语,in small.,with members.
最后at the level of the entire society 也是状语.谢谢您！十分感谢！with members ranked on a more or less equal footing as to wealth,status,and privilege,是不是插入语？是不是前两句开头都是介词，所以认定就不是主语了呢？不算插入语吧。确实因为有介词，所以是状语。