I have received a peer-reviewer's comment that states that my manuscript needs to be reviewed by experts on two different fields. Is it possible that I am being asked to find those two experts myself and ask them to review my manuscript, or is this probably a mistake/missunderstanding (that is, maybe that comment was not meant to be sent to the manuscript's author)?
Without seeing the actual text, I would guess you are mistaken or the review has a confusing grammatical mistake. The peer reviewer normally addresses the review to the editor, not the author. The reviewer is telling the editor that they should select other reviewers. It is possible that the editor has already done this. (Did you receive more than one review?) Probably there is no need for you to do anything.