See Secret Society.
1- Dreaming of belonging to a brotherhood indicates our need to belong to a group of like-minded people. This could be something in the nature of a trade union, or of the Freemasons. We all need approval from our peers, and such a dream indicates the way we handle ritualised group behaviour.
2- Any grouping of the masculine usually alerts us to the many sides and aspects of the masculine personality.
3- The Priesthood.