Macrodactyla doreensis (( LTA )) do not naturally split.
An Anthony has made some claims about doing this with every hosting anemone. However, no actual proof has ever been given -- so I would not put any stock on those claims.
Been in this hobby for 20+ years, have yet to see any actually proof of an M. doreensis being successfully* split.
IMO/E, enjoy your recovered anemone.
* --- success meaning both halves alive after a year.