What were Rudy Giuliani's business dealings in Ukraine?

It was another day of revelations in the saga of President Trump’s dealings with Ukraine, which prompted the impeachment inquiry. What was Trump’s personal attorney, Rudy Giuliani, doing in that Eastern European country? What did the president know about the whistleblower complaint -- and when? Yamiche Alcindor joins Judy Woodruff to discuss the latest and put it into context.