As with Android 4.2 and above Developer Options are simply hidden under Settings.
But, don’t worry. It’s rather simple to get it back. This method works for any nexus device with 4.2 and above, for HTC One it’s a slightly different but similar procedure.
Go to Settings > About tablet (it’s just About on a phone), find Build number. Touch that seven (7) times in a row, it will start counting after 3rd time or so. And, then you will get a “you’re now a developer”. That’s it. Easy, huh?