Operator receive and transmit paths separately

Hi all,

I would like to implement a RF record and playback system which is
similar to https://decibel.ni.com/content/docs/DOC-22174.
When it is recording, just receive path is active. During playback, just
transmit path is active.
How can I operator receive and transmit paths separately in a top block?
Or should I create two top blocks?

Best regards,
Damon