I want to call a function or change the value of variable/s which is there inside another controller. I looked online for the solution and understood that I have to create a service and use it inside both the controller, however I am not able to understand that how service will have access to $scope.home_main and  $scope.home_main variables as they are in different scope.
JS
 app.controller('Controller1', function ($scope, $window) {
     $scope.toggle = function() {
         $scope.home_main = !$scope.home_main;
         $scope.full_page_place_holder = !$scope.full_page_place_holder;
     };
 });
app.controller('Controller2', function ($scope, $window) {
    $scope.onTabSelect=function(){
    // here I want to call toggle function which is inside another controller.
    };
});
Updated HTML
<div ng-controller="Controller1">
    <div ng-hide="home_main"></div>
</div>
<div ng-controller="Controller2">
    <div ng-hide="full_page_place_holder"></div>
</div>
 
     
     
    