I created a few projects on an old iPad 2 years ago. The iPad broke down and I have had no more Apple products since then. Now I've set up an installation of macOS High Sierra in VMware, and I want to retrieve those projects uploaded to iCloud, from an iPad running iOS 6.1.3 (that's the last time I opened GarageBand on the iPad). I can confirm that the projects are still there by checking the usage of my iCloud space.
I tried launching Library while holding down the Alt key, and it showed me the "Mobile Documents" folder. However when I double-click on that folder, it jumps to my "iCloud Drive" folder, where I can't see anything (I just upgraded to iCloud drive).