Is it possible to filter rostopic echo by node?

edit

No, I don't believe that is currently supported (as of Kinetic/Melodic).

rostopic echo does support a --filter expression:

  --filter=FILTER-EXPRESSION
                        Python expression to filter messages that are printed.
                        Expression can use Python builtins as well as m (the
                        message) and topic (the topic name).

However I don't believe that has access to message metadata (as opposed to the message data itself) which is what you would need.