Oh, dear.
Predicate nominative is an old-fashioned term, derived from Latin grammar, where it contrasted with the predicate accusative employed with causatives. It's really out of place in English-as-we-have-now-come-to-understand-it, since English adjectives have no case; English nouns have only 'base' and 'possessive' cases; and even those English pronouns which distinguish 'subject' and 'object' cases do not employ these in the same way as the Romans employed the nominative and accusative cases in predicate complements.
Terminology is varied, but I think you will be understood if you call those predicate complements which describe or identify the subject subject PCs and those which describe or identify an object object PCs. If you hunger for more adjectival forms, try subject- and object-oriented; the -ive affix, to my mind, just confuses the issue and the reader.