Hi @ServiceNowEmp 
We can use $emit, $broadcast and $on to send and recieve the data.

- Example by using $broadcast

Include below code in client controller on source widget to send data.
$rootScope.$broadcast('dataEvent', data);

Include below code in client controller on target widget to recieve data.
$scope.$on('dataEvent', function (event, data) {
console.log(data); // 'recieved data'
});

- Example by using $emit

Include below code in client controller on source widget to send data.
$rootScope.$emit('dataEvent', id);

Include below code in client controller on target widget to recieve data.
$scope.$on('dataEvent', function (event, data) {
console.log(data); // 'recieved data'
});

Note : According to ServiceNow San diego docs, Avoid the use of $rootScope.$broadcast() because it can cause performance issues. Reference link - Using AngularJS Events with Widgets

Hi @ServiceNowEmp 

Detailed article about widget communication : How to communicate between widgets in Service Portal