Hello.
Do you mean to search for other d2jsp users? You have the “user search” function, located here:
https://forums.d2jsp.org/tools.php?a=2If you mean searching for other users posts, the only solution would be to go to his/her profile, and click on “search all posts”, and then follow the guidelines. That costs 5 FG, up to 500 search articles.
Best regards ^_^