Hello Pedro.

The way that the SaveFile WebBlock is implemented won’t allow you to provide that kind of paths. It just expects the Filename. To achieve what you want you’ll have to change the SaveFile javascript to use more sophisticated logic. One example is using the resolveLocalFileSystemURL
 
window.resolveLocalFileSystemURL(cordova.file.externalDataDirectory, function(dir) { });
 
For more examples you’ll have to take a closer look at the Cordova File Plugin – Where To Store Files
 
Thanks