You would want to use CompressWorkspace. Specify the same savepoint for firstSP and secondSP and set the compress_view_wo_overwrite parameter to true. So, for example:
SQL> exec dbms_wm.compressworkspace('LIVE', true, 'SP1', 'SP1') ;
This would need to be done for each savepoint where you would like to remove the history. The procedure would remove all rows for each primary key value, except for the latest one within the savepoint. It cannot be done on a range of savepoints at the same time, as that would remove the previous savepoints, as you pointed out.
Excellent, thanks alot!