In the public hearing of Sondland today, Nunes repeatedly referred to a private deposition (apparently on Saturday) of a person whose name he did not disclose but who is apparently very important because he/she was "in charge" of the foreign aid. Nunes lamented that this person's deposition cannot be publicly discussed and that apparently he/she won't be called to publicly testify. Who is Nunes talking about?
N.B. If you think this question is asking for speculation (3 VTCs seem to think so), consider it as: who was deposed on Saturday (the list can't be that long and the names are, I believe, public even for the private depositions, i.e. only the actual contents of deposition is private) that can reasonably said to be involved with directing US aid?
(I've managed to track down a recording of what I saw live, in which Nunes makes that statement; the "in charge" bit is said after Nunes' minute-long digression on Watergate. Nunes summarizes his points again toward the end of that segment.)