quick terminology check:
theres on one-step way to export a SEQUENCE into separate chunks based on CHAPTER MARKERS.
there would a ways to do it based on a few steps, but are you working with a sequence, or a single clip / file?
in that case MARKERS in the clip can easy be converted to subclips that can be batch exported.
you can batch export as reference movies (non self contained) which would make it fast.
if your file is an export from a sequence that had chapter markers, FCP doesn't see those markers anymore, unfortunately.
v simple to add them back:
DUPE the edit sequence w the markers,
delete the contents,
place the export in the sequence
select it,
no navigate marker to maker (shift down arrow) and just add a marker each time (m)
so :
shift down arrow, m, shift down arrow, m, shift down arrow, m, . etc.
export file now has all the markers,
copy / paste back to browser (dont drag)
toggle the marker triangle,
grab all markers,
Apple U to make subclips.
if you r timeline is bristling with markers other than chapter markers, open the project settings, (can never remember way menu that's under)
and turn off marker colours there than purple.
(should work, although i haven't done this)
hope that helps,
nick