Gab search is under development.
-Search for people
-Search for groups
-Search posts of your own + folks you follow
-Search results now show link/url results

Enter your search text, click the magnifying glass or hit the enter key.

On a gab post with a link.
"View Link Feed" click on any link that has a link in a post.  Search results will reveal other posts with that link.

Sub-menus can sort your search