In actions where there are several plaintiffs or several defendants, the costs shall be apportioned according to the several judgments rendered; and where there are several causes of action embraced in the same petition, or several issues, the plaintiff shall recover costs upon the issues determined in the plaintiff's favor, and the defendant upon those determined in the defendant's favor.
Iowa Code § 625.4
Apportionment between heirs and devisees, §633.476