gistfile1.txt

{
    "type": [
        "h-entry"
    ],
    "properties": {
        "published": [
            "2017-01-01 12:00:00"
        ],
        "checkin": [{
            "type": [
                "h-card"
            ],
            "properties": {
                "name": [
                    "Awesome Venue"
                ],
                "url": [
                    "https://foursquare.com/venue/12345"
                ]
            }
        }]
    }
}

$hCard = $request->input('properties.checkin');