Aggregating models "through" other models in SQL?

I have a sequelize based backend express API. In my sequelize models, a Citizen belongs to a Street which belongs to a Town, which belongs to a State. I can count the citizens in a Street easily like:

return db.Citizen.aggregate('value', 'count', {
    where: { 
         '$Town.name$': townName
    },
});

However, I would like to be able to count the citizens in a Town or State, even though Citizens aren't directly associated with those models. Is that possible and if so, how could I do it?

via George Edwards