ex.js

data = {
    state: {
        users: {
            foo: {name: 'Foo'}
        }
    }
}

tree = {
    state: new Model(data, 'state'),
    dummy: new Model({
        xxx: [1,2,3]
    }),
    object: {
        a: 1,
        b: 2
    }
}

state = Tag.create('state')
props = Tag.create('props')

target = state`users.${props`id`}`

user = target.resolve(tree, {
    id: 'foo'
})