After extracting the zip file you should have a folder which is called
CA-CentralProvTopo.gmapi from your screen shot that has happened. The files and folders you see are what should be there.
First, it's great that you are offering all these maps for download. But I'm sorry, what you posted is not correct. I have to ask, do you actually have a Macintosh? Unfortunately, a lot of the mapmakers here don't and make some wrong assumptions as a result. What you describe would only be correct if:
1. You are using a Windows computer and not a Mac
or
2. If you are using a Mac but have not properly installed Basecamp/Mapmanager/MapInstall.
When you install them correctly, you will NOT see what is shown in the screenshot. After installation, it changes the way .gmap and .gmapi folders are displayed. They will NOT look like folders anymore, they will look like DOCUMENTS.I just downloaded your map on my Mac and here's what a Mac user *should* see. YOU SHOULD NOT SEE ANY FOLDERS AT ALL. There should just be an icon that you double-click to install.
As I have posted in the other thread, he needs to re-install Garmin's software. Sometimes this happens. IIRC, Garmin has a version of Basecamp at the Mac App Store, and I think that is often the problem, it may not include MapManager, not sure. Anyway, downloading and re-installing from the link I posted in the other thread should fix this problem.
Also, @LostNeedToBeFound, please don't post duplicate threads. It just creates confusion when people are trying to answer you in two different places, as you can see here. Thanks.