Hey @Quirkz!
This is possible, though it certainly could be better documented. Can you try using a structure similar to this one?
[
{
value: 1,
label: "Option 1",
children: [
{ value: 1.1, label: "Option 1.1" },
{ value: 1.2, label: "Option 1.2" },
],
},
{
value: 2,
label: "Option 2",
children: [
{ value: 2.1, label: "Option 2.1" },
{ value: 2.2, label: "Option 2.2" },
],
},
]