SailfishOS from Jolla has been rolling out – since some times already – Sailjailing, which is a welcome feature. Unfortunately, the applications are not following, making many of them quite unusable since they can access, basically only $HOME/Document by default. Taking the example of the excellent File Browser, how to make it back to something usable is to un-Sailjail it. Of course, you need to understand that this means that you give access to all files in the file system to it. But this is what you want, right? How else it could work for you? But if you are interested in browsing only the files allowed for it, fine. This is how you can un-Sailjail it – and any other application – by creating the below file with the this content (you need to become devel-su, of course):

[root@Xperia10III applications]# pwd; cat harbour-file-browser.desktop