I have a form group which was build in ngOninit but later when one of that controls is clicked, I want to add few more controls to that existing form group based on the values got from another API in ngOninit. Below pictures shows the actual requirement. When I click on other role, I want to show other role controls which I've got from an API. since I'm new to angular2, can anyone help me to get out of this problem? Continue reading...