When belgrano is the home (1st leg) what is the  home (2nd leg)?
CREATE TABLE "losers_knockout" (
  "home_1st_leg" text,
  "home_2nd_leg" text,
  "1st_leg" text,
  "2nd_leg" text,
  "aggregate" text
);
SELECT "home_2nd_leg" FROM "losers_knockout" WHERE "home_1st_leg"='Belgrano';