If the currently opened file is the index. docbook file, then simply leave Current Working Folder checked. If it is not, then uncheck Current Working Folder and enter the folder of where index. docbook can be found.
Si el fitxer que està obert actualment és index. docbook, simplement deixeu marcat Carpeta de treball actual. Si no, desmarqueu Carpeta de treball actual i indiqueu la carpeta en la que es trobi index. docbook.