AngularJS toggle using same functions

HTML

<div ng-app="app">
    <div ng-controller="CommentController">
        <div ng-repeat="list in lists">
            <button ng-click="hiddenDiv = !hiddenDiv" class="review">{{lists[$index]}}</button>
            <div ng-show="hiddenDiv">This is the div to be toggled on clicking any of the above button. And they do so as they make use of <i>same function on click.</i>

            </div>
        </div>
    </div>
</div>

CSS

body {
    font-family:sans-serif;
    background-color: #f5f5f5;
}
.review {
    margin-bottom: 12px;
}

JavaScript

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

app.controller('CommentController', function ($scope) {
    $scope.hiddenDiv = true;
    $scope.showDiv = function () {
        $scope.hiddenDiv = !$scope.hiddenDiv;
    };
    $scope.lists = ["one", "two", "three", "four", "five"];
});