gistfile1.rb

def expand_keys(key, value)
  if File.dirname(key) != "/"
    return expand_keys(File.dirname(key), { File.basename(key) => value })
  else
    return {File.dirname(key) => { File.basename(key) => value }}
  end
end

data = {
   "unpacked" => {
      ".files" => {
         "mime" => "text/plain",
         "sha256" => "uzgc7EfJR9tYpyNn4r8FSWfNahxPdsJBG7Gs9rhlQiY"
      },
      ".ldig-unpack.pid" => {
         "mime" => "text/plain",
         "sha256" => "3oBDw7Sl4mtSlot8006M5tuKen+fq7ihmnPOhzYmlEw"
      },
      ".origin" => {
         "mime" => "text/plain",
         "sha256" => "EkLHkyBEpI6hQlsz7pdLXjKSvH0RBgpXfaHSniN+rRw"
      },
      "_service" => {
         "mime" => "application/xml",
         "sha256" => "0S_tvzccZNdH7EA9cWZ6VKOaVCiy5dxnjz61efbKhsk"
      }
   }
 }

final = data["unpacked"].map do |k, v|
  expand_keys(File.expand_path(k), v)
end

require 'pp'
pp final