node modules problems

1.js

var foo = require("../../../lib/foo");
var bar = require("../../../lib/bar");
var baz = require("../../../lib/baz");
var quux = require("../../../lib/quux");

2.sh

exports NODE_PATH=$NODE_PATH:./lib

3.js

var foo = require("foo");
var bar = require("bar");
var baz = require("baz");
var quux = require("quux");

4.sh

heroku config:set NODE_PATH=./lib

5

web: node www/app.js
events: node qhandlers/index.js

6.json

{
  "name": "signalleaf",
  "version": "0.0.1",
  "private": true,
  "dependencies": {
    "foo": "./lib/foo",
    "bar": "./lib/bar",
    "baz": "./something/baz",
    "quux": "./another/quux"
  }
}

In 6th case how can I write require? require('foo/subfoo') ?