Richard,

To make sure I understand what you want>
I assume you have one stave with Chords of a song. You want now to split the notes of the chords,
the top note to track 1, the middle note to track 2, the third/bottom not to track three.

Then I suggest to try the following.
Add staves to your notation.
Select the stave with chords.
Use the menu region - Filter notes in current region - filter top notes. This slect all top notes of the chords. Now you can copy and past these top notes onto one of the empty new staves.
After that delete all the selected top notes in the chord track.
You can repeat this procedure more time to copy the second an third, may be fourth note of the chord track to other staves.

If you want to keep your the chord notes in the chord track, then you shuold first make a copy of the Chord track, which you preserve as backup.

I hope this is what your looking for.

Cheers Jaap