See above the world cup match schedule [1], for another other examples with geo tree (e.g. country/province/city/district/etc.), see the Belgian Football clubs, for example [2] or for yet another example the Football leagues [3] with tiers (1,2,3, etc.) and cups and supercups, playoffs, etc. The .txt version are pretty compact with "tight" / strict error checking and JSON, YAML and friends I'd say it would be 2x, 3x or even more effort / typing.
[1]: https://github.com/openfootball/world-cup/blob/master/2018--...
[2]: https://github.com/openfootball/clubs/blob/master/europe/bel...
[3]: https://github.com/openfootball/leagues/blob/master/europe/l...