try ruby module and class

module Dojo
  A = "Dojo - A"
  B = "Dojo - B"
  class Dojo_child
    def print_a
      p "Dojo_child print_a - A: #{A}"
    end
  end
  
  module Kata
  	A = "Kata - A"
    class Kata_child
      def print_b
        p "kata_child print_b - B: #{B}"
      end
    end
    
    module Roulette
      A = "Roulette - A"
      B = "Roulette - B"
      class Roulette_child
        def print_b
          p "Roulette_child print_b - B: #{B}"
        end
      end
      
      class ScopeIn
        def push
          p "A: #{A}"
          p "B: #{B}"
          Roulette_child.new.print_b
          Kata_child.new.print_b
          Dojo_child.new.print_a
        end
      end
    end
  end
end

Dojo::Kata::Roulette::ScopeIn.new.push

# output
# "A: Roulette - A"
# "B: Roulette - B"
# "Roulette_child print_b - B: Roulette - B"
# "kata_child print_b - B: Dojo - B"
# "Dojo_child print_a - A: Dojo - A"