Multi-Select for boolean values

[smox]

Hi!

My problem is, that I want to build a multi-level multi-select form and I need different boolean values in different levels.

Currently I use a table with a list of checkboxes (about 30 different values), but it would be much better If I can use something like this:
{
"type": "array",
"items": {
"type": "string",
"enum": ["value1","value2", ... "value>8"]
},
"uniqueItems": true
}