Pressing someone's claim while having a smaller personal claim should give you your claimed land.

[onodera]

Let's say I am a king of Poland who has a claim to a duchy in Lithuania.
If I press someone's claim to the *kingdom* of Lithuania and win, they should get the kingdom, but I should get the duchy.

 

[Sondrety]

CK casus belli system has always lacked the ability to press more than one thing at the same time. It's really annoying. If you are De Jure king of Ireland then you should be able to press all your claims against a liege at the same time. Anything else is just silly. If you have the possibility to press more than one claim inside a kingdom, you should be able. It would be cool and somewhat realistic for a contender to bring his own nobility with him.