Reuven appointed Shimon to check his flat for chametz on the night of 14th of Nissan since Reuven was going away for Yom Tov. May Shimon in turn appoint Levy check the flat instead?
The shaliach can certainly make another shaliach to check the apartment, because the law is that one envoy can appoint another.
The question is whether this applies even for nullification (bittul), because bittul is speech alone, and for speech alone (mili) an envoy cannot appoint another envoy.
However, I saw in the commentary Misgeret Zahav on the Kitzur Shulchan Aruch (111:16) that because this is speech that executes a “deed,” in this case an envoy can appoint another envoy even for nullification.