RapidWeaver 6 saves your project files as .rw6 files. It’s a best practice (aka my recommendation) to store all sandwich files in the same location.
I’ve accidentally saved my project files in the wrong spot a few times… one time in my trashcan. RapidWeaver does not forever remember the folder where you’re saving all your files, so often if you work in another folder and then start a new project RapidWeaver will go there when you first save and if you type and click buttons faster than your mind sometimes you’ll accidentally save your file in the wrong spot.
Apple’s Finder has a built in search section, though it is not the friendliest and typically limited by the folder or sections you are already in. Instead use Apple’s spotlight search and you’ll easily locate your files.
If you cannot remember what you named your file or want to locate all your RapidWeaver project files then type in “sandwich” and they will all appear.