I am trying to group and sub-group

const [
    { type: "agency", properties: 10 },
    { type: "host", properties: 50 },
    { type: "agency", properties: 40 },
    { type: "landlord", properties: 50 },
    { type: "host", properties: 80 }
    ...
];

pipeline.push({
    $group: {
        _id: "$type",
        "All": { $count: { } },
        "Below 30": {
            $sum: {
                "properties": {
                    $gte: 0,
                    $lt: 30
                }
            }
        }
    }
});

This code is obviously not correct. Does anyone know how to do this ?

Daniel