A small dot release of Google Play Music is hitting the Play Store that brings back a menu option and other small improvements. The updated build is version 7.4 for those keeping score and with it you will find that the Recents option has returned to the main menu or navigation drawer of the app. This feature disappeared late last year when Google started injecting machine learning into the app so it could better learn your listening preferences. Since then, your Recents appeared as a button on the main display of the app (but it only shows your downloaded music if you are in offline mode)
The return of Recent to the menu should clean things up a bit whether you are online or offline and make it easier to find the music you have recently listened to in chronological order.