tes.js

var getPerm = (reducedWordList) => {
   var sevenLtrWords = _.filter(reducedWordList, (word) => {
       return word.length == 7;
   }); 

   var fourLtrWords = _.filter(reducedWordList, (word) => {
       return word.length == 4;
   }); 

   async.each(sevenLtrWords, (i, cb) => {
       async.each(sevenLtrWords, (j, cb) => {
           async.each(fourLtrWords, (k, cb) => {
               console.log(i + " " + j + " " + k); 
               cb();
           }, (err) => {});
           cb();
       }, (err) => {});
       cb();
   }, (err) => {});
};