It works partially. Now, when I select the option, the fields will hide, but an empty metabox will remain visible (see image). Is there a way to hide the box as well?

Thank you so much for the help.

Can use piklist_part_process so that the meta-box will only appear if the condition of another field is true after the post has been saved?

https://piklist.github.io/docs/actions-filters/filters/piklist_part_process/

For example:

add_filter('piklist_part_process', function($part) {
  global $post;

  // Make sure this is a post edit screen
  if ( $post && 'post' === $post->post_type )
  {
    // Check that this is the right folder and part
    if ( 'meta-boxes' === $folder && 'field-affiliate-buy-button.php' === $part['part'] )
    {
      if ( 'format-10' !== get_post_meta($post->ID, 'pit_article_format', true) )
      {
        return false;
      }
    }
  }
  
  return $part;
});

If yes, where I write the filter? Does all functions go in the functions.php regardless?

Thanks,

OK, I thinking I’m not doing the right thing here.
I’ve tried the piklist_part_process so that if another field is true on save, it will hide a meta-box block in the editor, but what I’m doing isn’t working, actually nothing happens when I save the post.

Here’s a better context:

I have a meta-box in the post editor backend with with radio options, which when on of the options is selected it loads post format for that particular post.
Now, I need to add a format that includes addition options, such as product pricing and buy button, but I need these options to appear only if a particular format is selected. The options can appear on-demand or after a save the post.

The problem that, as you said earlier, the conditional options for Piklist won’t remove the actual meta-box block if the format that triggers the options is not selected, and I want to avoid putting everything on a single mete-box, because I need to have the ability to organize and place metaboxes on different locations for a batter workflow.

This is the metabox with the new options that need to appear only when a new format option is selected:
File name: field-affiliate.php

<?php
/**
Title: Affiliate
Post Type: post
Collapse: false
*/
 piklist('field', array(
   'type' => 'group'
	 ,'field' => 'pit_affiliate_buy_button'
   ,'label' => 'Button'
   ,'description' => 'Affiliate button'
   ,'fields' => array(
                    array(
                    'type' => 'text'
                    ,'value' => 'button title'
                    ,'field' => 'button_title'
                    ,'label' => 'Affiliate button title'
                    ),
                   array(
                    'type' => 'text'
                    ,'value' => 'button url'
                    ,'field' => 'button_url'
                    ,'label' => 'URL'
                  ),
                   array(
                    'type' => 'text'
                    ,'value' => 'price now'
                    ,'field' => 'price_current'
                    ,'label' => 'Current Price'
                  ),
                  array(
                    'type' => 'text'
                    ,'value' => 'list price'
                    ,'field' => 'list_price'
                    ,'label' => 'List Price'
                  ),
                  array(
                    'type' => 'text'
                    ,'value' => 'discount price'
                    ,'field' => 'discount_price'
                    ,'label' => 'You Save'
                  )
   )// end of fields array

  ));
?>

This is the metabox that appears in the right-side of the editor, and includes the radio options:
File name: field-radio-formats.php

<?php
/*
Title: Article Formats
Post Type: post
Collapse: false
Capability: manage_options
Context: side
Priority: low
Locked: false
*/
  piklist('field', array(
    'type' => 'radio'
    ,'field' => 'pit_article_format'
    ,'label' => 'Normal'
    ,'description' => 'Choose article format. Default is Standard.'
    ,'value' => 'format-1' 
    ,'choices' => array(
      'format-1' => 'Standard'
      ,'format-2' => 'Background'
      ,'format-3' => 'Content Video'
      ,'format-10' => 'Affiliate Single'
      ,'format-99' => 'Legacy' 
    )
    ,'on_post_status' => array(
      'value' => 'lock'
    )
  ));
  
?>

Question 1: Is there any way to other than conditional option to show the entire metabox block only when a particular radio option is selected using the Article Formats metebox?

Question 2: If piklist_part_process should work to accomplish the behavior, is there something wrong with this code:

add_filter('piklist_part_process', function($part) {
  global $post;

  // Make sure this is a post edit screen
  if ( $post && 'post' === $post->post_type )
  {
    // Check that this is the right folder and part
    if ( 'meta-boxes' === $folder && 'field-affiliate-buy-button.php' === $part[''] )
    {
      if ( 'format-10' !== get_post_meta($post->ID, 'pit_article_format', true) )
      {
        return false;
      }
    }
  }
  
  return $part;
});

Thanks again.