title: Wordpress Multiple Group Category Filter
body: <p>How can I implement multiple group category filter using a widget? </p>
  
  <p>Example Category Hierarchy:</p>
  
  <p>Category1: Choicea1a and Choice2a</p>
  
  <p>Category2: Choice1b and Choice2b</p>
  
  <p>I want to display the two categories inside a select field containing their respective child categories. Is there an existing plugin for this?</p>
  
  <p>Thanks!</p>