D.D.

As we are incapable of asking a question for which we cannot imagine an answer, are you thinking of the Protestant answer, 'the priesthood of all believers'?

Or, some would say, "The Holy Spirit is the vicar of Jesus Christ."

Or, Seventh-day Adventism traditionally declares that every symbolism that construes a human as a symbolic mediator of salvation to other humans constitutes an anti-christ.

A one-word answer to your question might be:  directly

Perhaps you are thinking of the non-biblical notion of 'headship' in more practical terms, like who signs the check to pay the parish mortgage, who picks the music for the worship service, who reads the scripture, and so on.  

While 'headship' is understandably a contrived answer to a question the bible doesn't ask, for what congregational need do you find "headship" meaningfully practical, D.D.?