Saving an Item
Select the item (character, location, chapter etc) on the tree and right mouse click.
On the pop up menu choose the 'Save...' option. E.g. when saving a character choose 'Save Character to a file'
Loading an Item
Select the parent item on the tree. E.g. to load a character select the 'Characters' item.
Right mouse click and in the pop up menu choose 'Get xxx from a file'.