Back in 2012, Gmail enhanced the search feature by showing relevant emails, Google Calendar events, Google Drive files as you type your query. A similar feature is now available in Google Calendar and Google Drive.
For example, you can type a query in Google Calendar and find emails and Google Drive files, in addition to Google Calendar events. Click one of the results and it opens in a new tab.
Google Drive shows Google Calendar events and results from Gmail. If there are no Google Drive results, you'll see this message: "there are no recent records that match your search".
{ Thanks, Angelo Giuffrida. }