votes with active model serializer

vote_group_serializer.rb

class VotesGroupSerializer < ActiveModel::Serializer
  attributes :group_name
  has_many :votes
end

vote_serializer.rb

class VoteSerializer < ActiveModel::Serializer
  attributes :created_at, :user, :hashtag
  def user
    {id:object.user.id, username:object.user.username}
  end
  def hashtag
    {id:object.hashtag.id, name:object.hashtag.name}
  end
end

your_controller.rb

render json: {
  near_me: {
    count: @near_me.count,
    votes_groups: ActiveModel::ArraySerializer.new(@votes_groups, each_serializer: VotesGroupsSerializer)
  },
  votes: ActiveModel::ArraySerializer.new(@votes, each_serializer: VoteSerializer)
}