Asynchronous process

Not. That's the whole purpose of an async process. You do not care about the output. If you need the output, make it a synchronous process.

Hello [mention:23b56b00ee924454b087103e2086677d:e9ed411860ed4f2ba0265705b8793d05] 

What is your use case? Are you aware that we use Asynchronous when there is no dependency of data that is altered in the child process for the parent process?

docs.appian.com/.../Sub-Process_Activity.html

YOu have to use sync process if you want to get the data as an output... but if you need yo use the data further (in another process); you can store it in database and read when needed

Go with synchronous process. That is the only way you can use the output  data.