If a manual adjustment is completed via the form using the "Data Source Drill" screen, you will be able to see the break down within the manual adjustment screen.
Multiple adjustments can be entered in this screen and the system will consolidate them for the individual form attribute.  This is limited to an individual form attribute, and will not map to other forms automatically.
If the "Manual Input" screen is used to add in adjustments, only the entry that was entered will be used.  i.e. Your new adjustment will overwrite previous values.