可以通过以下方式实现：

# config/initializers/autoloading.rb

module Domains
end

Rails.autoloaders.main.push_dir(
  "#{Rails.root}/app/domains",
  namespace: Domains
)

# The next additional lines are necessary in Rails < 7.1.
domains_dir = "#{Rails.root}/app/domains" # has to be a string
ActiveSupport::Dependencies.autoload_paths.delete(domains_dir)
Rails.application.config.watchable_dirs[domains_dir] = [:rb]