Don't use a for-loop, that's how you'd do it in language like C, in Ruby we have abstractions (or can build them if not present) like [Enumerable#any?][1]:

    receive_payment_on = config[:sections].any? do |section|
      if section[:applicants]
        section[:applicants][:sections].any? do |app_sec|
          app_sec[:employment] && app_sec[:employment][:receive_payment_on]
        end
      end
    end

  [1]: http://www.ruby-doc.org/core-2.0/Enumerable.html#method-i-any-3F