As long as you have not saved the data, you can reset all changes made to an item as follows:
Select the required item(s).
Choose the pushbutton with the quick in fo text Undo Change.
To reset a split:
Position the cursor on the subitem concerned.
Choose the pushbutton with the quick in fo text Undo Split.
If several split items have been created for a split, and you want to reset all of them:
Position the cursor on the original item concerned.
Choose the pushbutton with the quick i nfo text Undo Split.