How is your music stored on the MyCloud? Is it in a hierarchical structure, e.g.
If so, then it appears that you are not seeing the file server using FileBrowser, but possibly looking at one of the DLNA media server views.
If not, and your music is simply stored as a flat structure:
then the problem is with your file system hierarchy. A file manager doesn’t usually present different views based on the metadata (unlike a media server), which is what you need if you want to be able to browse by different criteria.
I’ve used FileBrowser on an iPad, and recall it to be pretty good, as file managers go.
Of course, it could be that FileBrowser has been dumbed down to the iOS “you don’t need to worry your pretty little head about where files are stored, your clever iThing will do that for you” model. I liked FileBrowser because it behaved like a real man’s file manager, presenting a file system hierarchy that I could keep track of, and put things where I wanted them, not where the Ghost of Steve Jobs thought it would be a good place to put them.