When selecting the recipient for a report or BI message, Kiwi allows to select any public channel or individual person.
Initially Kiwi won't be able to post into private channels, since Kiwi can not "see" that this channel exists. For Kiwi to be able to post into private channels, someone within the channel needs to invite the Kiwi bot into the channel either by clicking the "Invite more people" link or using this command:
Afterwards the private channel is selectable as a recipient.
Note: You can not post into a (private) conversation/direct message, even when Kiwi is part of the conversation.