deep_finder.rb

class DeepFinder
  attr_reader :accum

  def initialize(h, key)
    @accum = []
    @h     = h
    @key   = key
    dig @h
  end

  def dig(h)
    h.each do |k,v|
      if k == @key
        @accum << h[k]
      elsif v.is_a?(Hash)
        dig(h[k])
      elsif v.is_a?(Array)
        v.each do |item|
          if item.is_a?(Hash)
            dig(item)
          end
        end
      end
    end
  end
end