Page layout snippet of a single picklist value. Notice the oAAA in the validFor. The base64 value needs to be decoded to determine which parent items the dependent picklist value is allowed for. See https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_calls_describesobjects_describesobjectresult.htm for more info.
{
"active": true,
"defaultValue": false,
"label": "Canceled",
"validFor": "oAAA",
"value": "Canceled"
}