How To Search My Own iCloud for Files Made On Computer I Don’t Have Anymore?

Over the years and since iCloud was invented, I have used 3 computers. Two of which belonged to other organizations I worked for. However, I backed everything up to iCloud. Now, I want to find documents I know I have, or slide shows I know I have, from 7 years ago, and I can find no way to search for them in iCloud. I cannot search my computer because they were made on another computer. Anyone know how I can search iCloud under these circumstances?
I am wasting so much time scrolling through SO MANY files and documents to try to find older files made on a computer I used to have.
—–
Cevon Lane