The catch is that almost every formal group of people has a "distinguished member". Any term implying a group of people with some structure will thus imply the existence of special roles within the group. So there hasn't been much need in English for such a specific word.

In line with that, the best I can suggest is the word "organization". (I considered "society", but the more general meanings of that word probably mean it's not as useful.) An organization implies that a group has some internal structure, and that structure in turn implies that some members will have special roles, without necessarily implying the existence of a hierarchy.

If this suggestion isn't useful, you should provide some context as to exactly why you need such a word.

If you want to convey the idea of someone's who makes the final decision, whose word is respected and whose opinion is never disputed, consider the following options.

• He who must be obeyed. Better known as she who must be obeyed. Its meaning is self explanatory and in the OP's context this phrase might be said in all seriousness or in a lighter, more humorous tone of voice.
• He's the boss. Not exactly an idiom but it implies that you don't mess around with this person and whatever decision he makes is final. A related idiom is show somebody who's boss

We had had a special respect for my father in my family and his

opinions and ideas were always accepted by other family members and as they put it, he was the boss.

• His word is law. There's no use questioning any of his rules - his word is law around here.

• Say-so. Usually a permission or instruction to do something given by a figure of authority. Nothing happens without his say-so.

and as they put it, nothing was decided without his say-so

• Have the final say. In many families, the mother has the last say on the children's education and activities.

...We had had a special respect for my father in my family and his opinions and ideas were always accepted by other family members and as they put it, he had the final say.