Do you mean at the top of Finder windows, in the "Toolbar"?
If so, at some point in the past, you dragged (and dropped) a folder, document, or app icon from a Finder window to the Toolbar area of a Finder window. I guess you did it three times, since there are three question marks now. Where they are located in the Toolbar is where you dropped them. You may have done this unintentionally, while you were dragging an icon between Finder windows.
These are shortcuts; when you click on one in the Toolbar, it opens that folder, document, or app. Since the question marks appeared after you did some housecleaning on the Mac, they were probably shortcuts to three of those pictures or documents. And you maybe you did drop them onto the Toolbar by mistake. No big deal...
To get rid of them now, right (control) click in the Toolbar area. Select Customize Toolbar from the menu. A panel drops down with things you can customize in the Toolbar. With that panel showing, drag each of the three question marks off the Toolbar and release. It goes "poof" and disappears.
Unless you want to make some other changes to the Toolbar, click Done.