I don't know if I speak of the same thing. -Cmd-Option-click on a class name as NSWindow or UIWindow, or a protocol as UIApplicationDelegate. this should open the class or the protocol in a second pane. Is it what you mean ? If so, I tested both in Xcode 16.4 and 26ß7. It works as described in both.
Topic:
Developer Tools & Services
SubTopic:
Xcode