Right now, American politics is dominated by an impeachment inquiry into President Trump. The thing that caused this inquiry was a whistleblower's report about a phone call Trump made with the leader of Ukraine.
Who did the whistleblower give his report to? And, how did it become public information?
The whistleblower made his report to the Inspector General of the Intelligence Community on August 12, 2019. 14 days later (August 26), the Inspector General determined that it was a credible report of an "urgent concern" (the statutory standard for this sort of report) and forwarded it to the Director of National Intelligence to forward to the Congressional intelligence committees within 7 days as provided by law. The DNI decided that the complaint did not need to be forwarded and refused to send it to the committees. 7 days after the deadline (September 9), the IG sent a letter to the intelligence committees informing them of the complaint's existence, the IG's determination that it was credible, and the DNI's refusal to forward it. The next day, the House intelligence committee sent a letter to the DNI demanding the complaint; 3 days later (September 13), they issued a subpoena and a press release, announcing the complaint's existence.
Who did the Trump-Zelinsky phone call whistleblower report to?
Page 2 of IGIC Atkinson published report (26 Aug 2019) states that:
... As part of the preliminary review, the ICIG confirmed that the Complainant is “[a]n employee of an element of the intelligence community, an employee assigned or detailed to an element of the intelligence community, or an employee of a contractor to the intelligence community.” 6
That is the extent of knowledge of who the whistleblower reports to.