AngularJs same directive for multiple Element, how to change a Isolated scope value

Iam using a directive to form a select element, repeating the json and forming select for each element. Now change of first dropdown1 i need to change the allowed_values of dropdown2. My sample Code.

<div ng-repeat="(k,v) in data"> <dyna-select label=k field=v></dyna-select> </div> 

app.directive('dynaSelect', function() { return { restrict: 'E', template: `<div> <label>{{label}}</label> <select ng-options="items as items for items in field.allowed_values" > </select> </div>`, scope: { field:=?field, label:=?label } }; }); var data= { "dropdown1": { "allowed_values": [ "option1", "option2" ] }, "dropdown2": { "allowed_values": [] } }