This is one option that is not exposed in the globals file. For the browse function when file is selected from the select list on the left by default you start in root_URL/files/. You can adjust this in the config though to start you out in the root of the site.
Config file at:
iRite > editor > filemanager > connectors > php > config.php
In here find these two lines:
115: $Config['FileTypesPath']['File'] = $Config['UserFilesPath'] . 'file/' ;
116: $Config['FileTypesAbsolutePath']['File']= ($Config['UserFilesAbsolutePath'] == '') ? '' : $Config['UserFilesAbsolutePath'].'file/' ;
Just take out the file/ part and it should default to the root of your site.