The value of the parent form element option to filter this option. E.g. E.g. if this options set is for Cities (Sydney, Brisbane, Melbourne) and the parent options set is for States (NSW, QLD, VIC) and this option represented Sydney, this value would be "NSW".
The label to display in the forms builder when selecting an element to match the "value" property. E.g. if this options set is for Cities (Sydney, Brisbane, Melbourne) and the parent options set is for States (NSW, QLD, VIC), this label could be "State".