nested

# File actionpack/lib/action_dispatch/routing/mapper.rb, line 1754
        def nested(&block)
          unless resource_scope?
            raise ArgumentError, "can't use nested outside resource(s) scope"
          end

          with_scope_level(:nested) do
            if shallow? && shallow_nesting_depth >= 1
              shallow_scope do
                path_scope(parent_resource.nested_scope) do
                  scope(**nested_options, &block)
                end
              end
            else
              path_scope(parent_resource.nested_scope) do
                scope(**nested_options, &block)
              end
            end
          end
        end