Taxonomy hierarchy via separate dropdowns I am building a view that requires users to select from a drop down menu containing a list of taxonomy terms, which will then filter the view results based on those terms. So far, so good.

I want to make the dropdown menu with only all of parent taxonomy terms of a specific vocabulary so that when one of the parent terms is selected, a second drop down menu shows all of the children of the selected term.

How can I accomplish this, preferably without an extra module? I will consider any means to accomplish this goal.

More specifically, I am building a view based on states and counties, and want users to first select a state and then select from the list of counties for that state.
You probably won't be able to do that without some custom code.

An existing module for the purpose is Simple hierarchical select:


  Simple hierarchical select defines a new form widget for taxonomy
  fields to select a term by "browsing" through the vocabularies
  hierarchy. The widget is available in node forms and as Views exposed
  filter. 


https://www.drupal.org/project/shs

There is also the more full featured module Hierarchical select