hello sir,
I really need your help.i want to make a multiselect dropdown in a text-field and in multiselect dropdown there is two dropdown must be open at single value select i.e. when i click on text-field it shows a category dropdown and when i choose any product from that it again show a next dropdown of their category value . when i select their category value then it must be count as a single select in text-field.

Same the thing you have seen in amazon web service page.please help me how can i write the code for the above problem using angular js.

As this is a forum for Responsive Site Designer, which is for creating sites without having to write code, I don't think you'll find many Angular.js users here.
That would be way off topic for this forum anyway.