The Search Menu

  Find (Ctrl+F) Find words or phrases within the article loaded in the article pane.
  Search (Ctrl+Shft+F) Perform searches for articles. You can perform plain text or regular expression searches (using PCREs) for the articles in the current newsgroup, or across all subscribed newsgroups. 
You can search article bodies, headers, or you can limit the search to the information on your local drive.
For details see:  Searching for Articles and the Search Window

  Search Google Groups Launches the system web browser and connects to Google Groups.
Notes:
·      You can set another browser to open the URL with Tools - Global Options - URL Hotlinks
·      You can set any URL to open with the Google button with this registry value:
...\System\DejaNewsUrl
To save the registry setting, Gravity can NOT be running.The Gravity installer may overwrite your custom URL, requiring a manual edit.
* Caution: Edit the registry at your own risk.