@Probertd8 @georgetakei End the current call you are in right now and accept the new one that's coming in / decline the new call coming in and keep being on the call you are on / put the current call you are on on hold and accept the new call coming in.
It's difficult to understand out of context like this, but if you're talking to someone on the phone and you hear that you're getting a new call, I think it's possible to figure out, even if not perfect.