I just ran into a similar issue, but on top of it affecting every instance, mine also has the added bonus that if I select “Custom”, it makes the entire group disappear.

piklist('field', array(
  'description' => 'Limit: 3 Sections',
  'type'      => 'group',
  'field'     => 'footer-widgets',
  'label'     => 'Footer Sections',
  'add_more'  => true,
  'validate'  => array(
    array(
      'type'    => 'limit',
      'options' => array(
        'min'     => 1,
        'max'     => 3
      )
    )
  ),
  'fields'    => array(
    array(
      'type'    => 'text',
      'field'   => 'title',
      'label'   => 'Title',
      'columns' => 6
    ),
    array(
      'type'    => 'textarea',
      'field'   => 'content',
      'label'   => 'Content',
      'columns' => 12
    ),
    array(
      'type'    => 'text',
      'field'   => 'link-text',
      'label'   => 'Link Text',
      'columns' => 4
    ),
    array(
      'type'    => 'radio',
      'field'   => 'link-type',
      'label'   => 'Link Type',
      'value'   => 'post',
      'list'    => false,
      'choices' => array(
        'post'    => 'post/page',
        'custom'  => 'Custom'
      )
    ),
    array(
      'type'    => 'text',
      'field'   => 'link-url',
      'label'   => 'Custom URL',
      'conditions'  => array(
        array(
          'field'     => 'footer-widgets:link-type',
          'value'     => array('custom')
        )
      )
    ),
    array(
      'type'    => 'select-post',
      'field'   => 'link-post-id',
      'label'   => 'Post to Link',
      'options' => array(
        'characters'  => 30
      ),
      'conditions'  => array(
        array(
          'field'     => 'footer-widgets:link-type',
          'value'     => array('post')
        )
      )
    )
  )
));

And because animated gifs are fun:

This is my contribution:

This code works perfectly but if I put it in a group/add-more field it doesn’t work anymore.

NO group/add-more

piklist( 'field', 
	array(
		'type'        => 'radio',
		'scope'       => 'post_meta',
		'field'       => 'katt_schedule_choice',
		'value'       => 'show', // Sets default to show
		'label'       => 'Choose a Break or a Presentation',
		'help' 		  => 'To build your schedule you can insert a presentation or a break.',
		'attributes'  => array(
		  		'class' => 'text',
								),
		'choices' => array(
				'presentation'  => 'Presentation',
				'break'         => 'Break',
		    				),
		  		
		)
);
 
piklist( 'field', 
	array(
		'type'        => 'text',
		'field'       => 'katt_schedule_break',
		'label'       => 'Break',
		'help'        => 'If you need to insert a break (Welcome, Coffee, Lunch ...) in your schedule, use this field.',
		'conditions'  => array(
      				    array(
					'field'   => 'katt_schedule_choice',
					'value'   => array( 'presentation' ),
					'compare' => '!='
    							),
    						),
		)
);

piklist( 'field', 
	array(
		'type'        => 'select',
		'field'       => 'katt_schedule_presentation',
		'label'       => 'Presentations',
		'help'        => 'Choose a presentation to build your schedule.',
		'conditions'  => array(
      					array(
					'field'   => 'katt_schedule_choice',
					'value'   => array( 'break' ),
					'compare' => '!='
    							),
    						),
		)
);

IN a group/add-more field:

piklist( 'field', 
		array (
		'type'     => 'group',
		'field'    => 'katt_schedule_group',
		'add_more' => true,
		'label'    => __( 'Presentation or Break' , 'katt' ),
		'help' 	   => __( 'To build your schedule you can insert a presentation or a break.' , 'katt' ),
		'fields'   => array(
		array(
			'type'        => 'radio',
			'scope'       => 'post_meta',
			'field'       => 'katt_schedule_choice',
			'value'       => 'show', // Sets default to show
			'label'       => __( 'Choose:' , 'katt' ),
			'attributes'  => array(
			  			'class' => 'text',
									),
			'choices' => array(
					'presentation'  => __( 'Presentation' , 'katt' ),
					'break'         => __( 'Break' , 'katt' ),
			    				),
			  		
			),
		array(
			'type'        => 'text',
			'field'       => 'katt_schedule_break',
			'label'       => __( 'Break' , 'katt' ),
			'help'        => __( 'If you need to insert a break (Welcome, Breakfast, Coffee break, Lunch ...) in your schedule, use this field.' , 'katt' ),
			'conditions'  => array(
	      					array(
						'field'   => 'katt_schedule_choice',
						'value'   => 'presentation',
						'compare' => '!='
	    							),
	    						),
			),
		array(
			'type'        => 'select',
			'field'       => 'katt_schedule_presentation',
			'label'       => __( 'Presentations' , 'katt' ),
			'help'        => __( 'Choose a presentation to build your schedule.' , 'katt' ),
			'conditions'  => array(
	      					array(
						'field'   => 'katt_schedule_choice',
						'value'   => 'break',
						'compare' => '!='
	    							),
	    						),
			)
		)
	)
);

Thanks Marcus,

Now I can see my two conditional fields and I’ve got the same bug as you.

I didn’t see in the Piklist “User Guide” that we need to reference the outside group name inside the conditional.
Where did you see this instruction?

I am having a similar issue, If the group does not have a field name, how would I reference it?

Here is my code:

<?php
/*
Title: User General
Description: General Info for all Users
*/

piklist('field', array(
'type' => 'select'
,'field' => 'user_country'
,'value' => 'US' // Sets default to US
,'label' => 'Country'
,'choices' => array(
  'AF'=>'Afghanistan',
'AL'=>'Albania',
'EE'=>'Estonia',
'ET'=>'Ethiopia',
'FK'=>'Falkland Islands (Malvinas)',
'FO'=>'Faroe Islands',
'FJ'=>'Fiji',
'US'=>'United States',
'UM'=>'United States Minor Outlying Islands',
'UY'=>'Uruguay',
'UZ'=>'Uzbekistan',
'VU'=>'Vanuatu',
'VA'=>'Vatican City (Holy See)',
'VE'=>'Venezuela',
'VN'=>'Vietnam',
'VG'=>'Virgin Islands (British)',
'VI'=>'Virgin Islands (US)',
'WF'=>'Wallis And Futuna Islands',
'EH'=>'Western Sahara',
'WS'=>'Western Samoa',
'YE'=>'Yemen',
'YU'=>'Yugoslavia',
'ZM'=>'Zambia',
'ZW'=>'Zimbabwe'
)
));

  piklist('field', array(
    'type' => 'group'
    ,'label' => 'Address'
    ,'fields' => array(
      array(
        'type' => 'text'
        ,'field' => 'user_address_1'
        ,'label' => 'Street Address'
        ,'columns' => 12
      )
      ,array(
        'type' => 'text'
        ,'field' => 'user_address_2'
        ,'label' => 'PO Box, Suite, etc.'
        ,'columns' => 12
      )
      ,array(
        'type' => 'text'
        ,'field' => 'user_city'
        ,'label' => 'City'
        ,'columns' => 5
      )
      ,array(
        'type' => 'select'
        ,'field' => 'user_state'
        ,'label' => 'State'
        ,'columns' => 4
		,'conditions' => array(
			array(
				'field' => 'user_country'
				,'value' => 'US'
				)
			)
        ,'choices' => array(
          'AL' => 'Alabama'
          ,'AK' => 'Alaska'
          ,'AZ' => 'Arizona'
          ,'AR' => 'Arkansas'
          ,'CA' => 'California'
          ,'CO' => 'Colorado'
          ,'CT' => 'Connecticut'
          ,'DE' => 'Delaware'
          ,'DC' => 'District Of Columbia'
          ,'FL' => 'Florida'
          ,'GA' => 'Georgia'
          ,'HI' => 'Hawaii'
          ,'ID' => 'Idaho'
          ,'IL' => 'Illinois'
          ,'IN' => 'Indiana'
          ,'IA' => 'Iowa'
          ,'KS' => 'Kansas'
          ,'KY' => 'Kentucky'
          ,'LA' => 'Louisiana'
          ,'ME' => 'Maine'
          ,'MD' => 'Maryland'
          ,'MA' => 'Massachusetts'
          ,'MI' => 'Michigan'
          ,'MN' => 'Minnesota'
          ,'MS' => 'Mississippi'
          ,'MO' => 'Missouri'
          ,'MT' => 'Montana'
          ,'NE' => 'Nebraska'
          ,'NV' => 'Nevada'
          ,'NH' => 'New Hampshire'
          ,'NJ' => 'New Jersey'
          ,'NM' => 'New Mexico'
          ,'NY' => 'New York'
          ,'NC' => 'North Carolina'
          ,'ND' => 'North Dakota'
          ,'OH' => 'Ohio'
          ,'OK' => 'Oklahoma'
          ,'OR' => 'Oregon'
          ,'PA' => 'Pennsylvania'
          ,'RI' => 'Rhode Island'
          ,'SC' => 'South Carolina'
          ,'SD' => 'South Dakota'
          ,'TN' => 'Tennessee'
          ,'TX' => 'Texas'
          ,'UT' => 'Utah'
          ,'VT' => 'Vermont'
          ,'VA' => 'Virginia'
          ,'WA' => 'Washington'
          ,'WV' => 'West Virginia'
          ,'WI' => 'Wisconsin'
          ,'WY' => 'Wyoming'
        )
      )
      ,array(
        'type' => 'text'
        ,'field' => 'user_postal_code'
        ,'label' => 'Postal Code'
        ,'columns' => 3
		,'conditions' => array(
			array(
				'field' => 'user_country'
				,'value' => 'US'
				)
			)
      )
    )

  ));
piklist('field', array(
    'type' => 'tel'
    ,'field' => 'user_number'
    ,'label' => 'Phone Number'
  ));
 
 
 ?>

When I select a country that is not the US, the entire group disappears instead of just the city and zip code. I think the solution that Marcus proposed would work if it had a field name, but I do not want my data serialized. I have almost the exact same code on a normal meta box and the condition works fine, but when using it on my user profile it does not work as desired.

thanks

@justin– We believe we have a fix for this issue. I will be sending you a beta version of Piklist in the next few days.