I think you have misunderstood either what I said or what they said.
https://variety.com/feature/who-votes-on-oscars-academy-awar...
Each person belongs to one of 17 branches. Each branch nominates for its own category — e.g., editors nominate editors, actors nominate for the four acting categories. Everyone gets to nominate best picture. For the final voting of the winner, all branches vote for everything.
