When loading the file browser from a ListIt2 instance as an admin user, the
"Current directory" is displayed in the top left of the GBFilePicker dialog, and
clicking on the icon to the left of this text takes the user to the main Uploads
folder.

Howevever, when logged in as a non-admin user, with all file permissions set
correctly in the Group Permissions, ListIt2 instance fields and GBFilePicker,
the "Current directory" doesn't display any folder name, and clicking the icon
produces the following error:

"Directory '/my/server/path/mysite.com/www/uploads/images/images/' not found!"

In the above scenario, the current GBFilePicker directory is
"uploads/images/content-blocks". The images within this folder are correctly
shown in the list, and subfolders also appear in the list, but it's not possible
to navigate above the "content-blocks" folder.

This has been tested on older versions of CMSMS, GBFilePicker and ListIt2, as
well as with a fresh installation with all the latest versions.

The problems this causes are:

1. It's not possible to navigate above the current folder.
2. It's not possible to jump to the main Uploads folder.
3. It's difficult for the user to determine which folder they're in to begin
with because I use different folders for different fields with ListIt2.