Can't find recently edited numbers file nor the folder the file was in

I have an iMac running High Sierra. I created a spreadsheet in Numbers a couple of months ago. I have been updating it a few times each week. Last edit was this month a couple of times. The Numbers file was stored in a folder named finance. When I tried to edit it yesterday, Saturday, I couldn't find the file nor the folder. I tried searching for the file and found a couple of files with the same name but they were older copies. I started the Numbers app and tried the "open recent" option in the file menu. I again found a couple of files with the correct name but they were the older files mentioned earlier. What could have happened to the file and folder? I suppose I may have accidently deleted them. Is there any way to tell? If I deleted them do I need a 3rd party app to try and recover them?