I am using Adobe Acrobat Pro ("Continuous Release" version 21.11.20039.0), I understand how to search multiple PDF's, but I want to constrain the search to multiple OPEN PDF's. I don't want to look in ALL the files in a folder, and I prefer not to move the relevant files to a subfolder (although that is the workaround hack I have to use for now).

You should add a feature that allows the user to search within OPEN documents. Please and thank you

(User context: I am working on a review article, and citing various published studies. I can't remember which one of 4 papers within the folder full of 50 papers I've read for this review that referred to a specific subject. I want to simply open the 4 candidate papers and search them to find the key word. I don't want to search all 50 in the folder, and I don't want to move these 4 to a subfolder just for this one little search.)