Google+ Photos has a few search filters that are pretty useful. You can find them if you click the small arrow from the search box: Auto Backup, Hangouts, Google Drive, Posts, Auto Awesome, Videos and more. The nice thing is that most of them are also available in Google Photos.
Google Photos has a search page that shows a few filters: Creations (replaces Auto Awesome), Google Drive, Video, Recently Added. Here are some searches you can use to bring back the filters from Google+ Photos:
#AutoBackup – shows all the photos automatically backed up from your mobile devices and desktop computers
#Desktop – shows the photos automatically backed up from your desktop computers
#Posts – shows the photos added to your Google+ posts
#All – shows all your photos
#PhotosOfYou – photos you’ve been tagged in
#CAMERANAME – replace CAMERANAME with the your camera’s model or brand to see all the photos taken with that camera. Some examples: #Nexus5, #Canon, #iPhone.