Questa è una domanda JavaScript, non necessariamente Meteor. Usa un for-in
ciclo per scorrere gli oggetti.
// This query returns an object
var MyObject = VideoCourses.find({'_id': 'jkwehrjewrew'}).fetch()[0].videos
// The object is brings back looks like this:
// {
// first: "firstvideo.html",
// second: "secondvideo.html",
// third: "thirdvideo.html"
// };
// Use a for-in loop to iterate through the object
for(key in myObject){
console.log("this is the key: ", key, ", and this is the value: ", myObject[key]);
};