gistfile1.js

var acl = require('../routes/middleware/acl');
var mongoose = require('mongoose');
// var config = require('../libs/configurator'); don't need this
var config = require('../libs/configurator');
var async = require('async');
require('../models')(mongoose);

// mongoose.models.Works.find({}).exec(function (err, works) { <-- Work should be singular, as in below
mongoose.models.Work.find({}).exec(function (err, works) {
  async.each(works, function (work, cb) {
    mongoose.models.Group.find({"featured._work": work._id}, function (err, groups) {
      if (err !== undefined) {
        throw err
      } else {
        work.featuredIn = _.map(groups, function(group) {
          _group: group._id.toString()
        });
        /*
          You need to run mongoose.models.Work.update() here after you've confirmed that there are
          matching groups. As is this will not actually persist your changes to the database
        */
      }
    });
  }, function (err) {
    process.exit();
  });
})