When you open a file dialog the directory will be the same as when you closed the last used file dialog. This applies to all open and save file dialogs.
The history button 
will allow you to navigate back to earlier used directories. The history is shared by all open and save file dialogs. The history is saved in the user settings so it is kept after restart or logging into a different machine. The region home and the user home are always listed in the history.
