Unlike iOS, OS X El Capitan defaults to a date sorting system that groups all your Notifications together by the date they were triggered. That’s super handy if you’re searching for a notification you got today, but don’t remember what app it came from. If, however, you want to sort by the app the notification is coming from, or–better yet–sort by date and app, you’re in luck.
Here’s how to choose a different option.
Assuming you still want your Mac to notify you at all, launch System Preferences from the Apple Menu or Dock and click on the Notifications icon.
Next, look in the lower left corner of the window for a drop-down menu called Notification Center sort order. Click on it, and you’ll have three choices: Recents, Recents by app, and Manually by app. The third option is fine if you like that sort of thing, and only want to browse what each of your apps has notified you about. The first option is the default El Capitan behavior, so you can leave it there, too.
The best option, though, is the second one. Not only do you get the benefit of finding a notification by the date it was triggered, which is helpful if you only remember when the notification happened but not from which app, but you also get to group things by apps, which gives the app sorting option a date-based super power, if you will.
Now, whether you remember the app that notified you or the day on which you were notified, you can find what you need with a quick check on your Mac notifications in Notification Center.
Via: Tech Radar