JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="myApp" ng-controller="BookingCtrl">
    <select ng-model="selected.site" ng-options="s.data as s.site for s in data" ng-change="updateSelectedBuildingsAndFloors()">
        <option value="">-- Site --</option>
    </select>
    <select ng-model="selected.building" ng-options="b.data as b.building for b in selectedBuildings">
        <option value="">-- Building --</option>
    </select>
    <select ng-model="selected.floor" ng-options="f.data as f.floor for f in selectedFloors">
        <option value="">-- Floor --</option>
    </select>
</div>

JavaScript

var myApp = angular.module( 'myApp', [] );

myApp.controller( 'BookingCtrl', ['$scope', '$location', function ( $scope, $location ) {

    $scope.selected = {};

    $scope.data = [
        {
            "id" : "0",
            "site" : "Brands Hatch",
            "data" : 0,
            "buildings" : [
                { "building" : "Building #1", "data":1},
                { "building" : "Building #2", "data":2 },
                { "building" : "Building #3", "data":3 }
            ],
            "floors" : [
                { "floor" : "Floor #1", "data":1 },
                { "floor" : "Floor #2", "data":2 },
                { "floor" : "Floor #3", "data":3 }
            ]
        },{
            "id" : "1",
            "site" : "Silverstone",
            "data" : 1,
            "buildings" : [
                { "building" : "Building #4", "data":1 },
                { "building" : "Building #5", "data":2 },
                { "building" : "Building #6", "data":3 }
            ],
            "floors" : [
                { "floor" : "Floor #4", "data":1 },
                { "floor" : "Floor #5", "data":2 },
                { "floor" : "Floor #6", "data":3 }
            ]
        }
    ];
    
    $scope.updateSelectedBuildingsAndFloors = function(){
        $scope.selectedDataArray = $scope.data.filter(function (data) { return data.data == $scope.selected.site });
        $scope.selectedData = $scope.selectedDataArray[0];
        if($scope.selectedData){
            $scope.selectedBuildings = $scope.selectedData.buildings;        
            $scope.selectedFloors = $scope.selectedData.floors;        
        }
        else {
            $scope.selectedBuildings = [];        
            $scope.selectedFloors = [];        
        }
        
    }    
}]);