how to have child options created

With new version "2.0.0-beta2.21617.1" of System.CommandLine, I would like to know two things.

(1) How can we create child option for command? Add option is clear for first level. I did not get an example how to do it for second level, so reaching out for help.

mycommand
[--organization "" [--organization-short ""]]

(2)
In earlier version, parse result used to print nicely on screen on the values entered. But, in new it does not print option/ value list.

var result = rootCommand.Parse();
Console.WriteLine(result.ToString());

[now]
ParseResult: ![ ConsoleApp1 ]