It cannot magically know about every file on your computer. You must navigate to a directory that might have it. You can go row-by-row to choose a replacement for each, but you must find and pick the file yourself. It does not need to be the exact same file, but it is usually better if it is. Otherwise, this dialog has a search button where you can choose a folder, but you need to at least navigate to a likely folder. It does not magically know which folder to search, and you can try more than one folder.