nextcloud-android/src/main/res/xml/exposed_filepaths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path
        path="log/"
        name="log"/>
    <external-path name="external_files" path="."/>
    <root-path name="external_files" path="/storage/" />
    <!-- yes, valid for ALL external storage and not only our app folder, since we can't use @string/data_folder
    as a value for 'path' attribute; in practice, we will only generate URIs in our folders, of course -->
</paths>