I thought we should have groups and tournament format posted here for reference:

A.                     B.                C.                D.
Poland               Russia          Spain            Angola
Côte d'Ivoire      Argentina      Iran              Philippines
Venezuela          S.Korea         Puerto Rico   Italy
China                 Nigeria         Tunisia          Serbia


E.                     F.                      G.                          H.
Turkey               Greece              Dominican Rep.      Canada
Czech Rep.         New Zeeland     France                   Senegal
USA                   Brazil                Germany               Lithuania
Japan                 Montenegro       Jordan                  Australia

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First two teams of each group advance into second round forming 4 new groups (I, J, K, and L)

Results from the first group stage carry over into the second round.

A¹ + A² + B¹ + B² = Group I

C¹ + C² + D¹ + D² = Group J

E¹ + E² + F¹ + F² = Group K

G¹ + G² + H¹ + H² = Group L

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Quarter-Finals:

I¹ vs. J²

K¹ vs. L²

J¹ vs. I²

L¹ vs. K²

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Semi-Finals

Winner of (I¹ vs. J²) vs. winner of (K¹ vs. L²)

Winner of (J¹ vs. I²) vs. winner of (L¹ vs. K²)

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Being there no surprises in the first group stage Spain and Serbia will join together in group J.

Winner of group J will have the chance to face team USA the earliest in the Finals (if they win their matches)

Loser has to play the USA in the semis (if they win their matches)


source: http://www.fiba.basketball/basketballworldcup/2019