No you can't do that. You can have Mitro/Sessegnon (bet builder) or Mitro/Salah (double) but that particular combination restricts the 'multiple' options. Usually two selections within the same game removes the option to combine them - not always, you can do goals/cards/corners treble for example - but goalscorers it doesn't let you outside of BBs, which you can't combine with other matches.