Will a person see everyone they knew in their life on the Plain of Gathering (Ard al-Mahshar)? Will some of them see each other in Paradise or Hell? Will they visit each other in the Barzakh after their death?

There is no evidence that a person will see everyone they knew in their life, whether in the Barzakh, or at the Gathering, or on the Day of Judgment, or in Paradise, or in Hell. Rather, the souls of believers who knew each other will meet in the Barzakh and visit each other in Paradise, and fathers and sons among them will be gathered in the same degree therein.