[{"comments":[{"user":{"_id":1,"username":"name1","type":"friend","profileImage":""}},{"user":{"_id":1,"username":"name1","type":"Nofriend","profileImage":""}},{"user":{"_id":1,"username":"name2","type":"friend","profileImage":""}},{"user":{"_id":3,"username":"name3","type":"friend","profileImage":""}},{"user":{"_id":4,"username":"name4","type":"NOfriend","profileImage":""}},]}]

db.collection.update({"comments.user._id":1,"comments.user.type":"friend"},{"$set":{"comments.$[element].user.profileImage":"new"}},{"arrayFilters":[{"$and":[{"element.user._id":1},{"element.user.type":"friend"}]}],"multi":true})