How to make a dynamic contact form in angularjs?

Question

JavaScript

Good time of the day.
There is a form in which there are many related elements that are displayed under certain conditions, for example:
In the drop-down list when you click on the "Question at work" item, the associated form "Question at work" appears below.
This nesting can be very deep. I am not strong in Angular, before that I used only knockout from similar ones, but not for such tasks. If you have any code examples, I'd appreciate it!