Invisible Files and Folders
By default, invisible files and folders are not shown in the file browser tab of the side panel.
If you want to see them at a given level of the files system hierarchy, right click on the desired folder name in the file browser within the side panel and toggle Show hidden files in the contextual menu.
Here is how to view all visible files and folders in the whole system:
This feature is very convenient for Mac users when used with caution, since combined with the Delete contextual menu in the file browser, it allows you, for example, to get rid of files generated by cvs on conflicts within bluefish.