Jazz combo - parts share the same chord symbols

Chords are linked to a specific staff. But you can very easily copy-and-paste them to all other staves.

1. Enter Chords on the first staff
2. Right-click (ctrl-click on Mac) the first chord symbol and choose Select → All Similar Elements
3. Copy
4. Go to the start of each staff and perform a Paste on each staff

Now your chord symbols are available on all parts.
Additional steps if you don't want them showing up all over the place in the combined score:

1. Select all but the top staff (click first measure of 2nd staff, shift-click last measure of last staff)
2. Right-click (ctrl-click on Mac) a Chord symbol within the current selection and choose `Select → All Similar Elements within Range´
3. Use the inspector (F8) to turn them invisible. Or use the shortcut key V

While the symbol itself is contents, and thus will be linked with the parts; the visibility of it is a layout option and specific to that part/score only.