Validation of field 1 or field 2

Hi there,

Do you mean that the third field will be displayed when at least first or second field is not empty?

Thanks.

Hey Infolu,

This can be achieve by using Compound Statements in Conditional Logic.
https://docs.metabox.io/extensions/meta-box-conditional-logic/#compound-statements

Here is my example, the field Address will visible when Full Name or Email has filled.

add_filter( 'rwmb_meta_boxes', function ( $meta_boxes ) {

	$meta_boxes[] = array(
        'id'         => 'personal',
        'title'      => 'Personal Information',
        'post_types' => 'post',
        'context'    => 'normal',
        'priority'   => 'high',

        'fields' => array(
            array(
                'name'  => 'Full Name',
                'desc'  => 'Full name',
                'id'    => 'name',
                'type'  => 'text',
            ),
            array(
                'name'  => 'Email',
                'desc'  => 'Email Address',
                'id'    => 'email',
                'type'  => 'email',
            ),
            array(
            	'name' => 'Address',
            	'desc' => 'Address',
            	'id' => 'Address',
            	'type' => 'text',
            	'visible' => [
            		'when' => [
            			['name', '!=', ''],
            			['email', '!=', '']
            		],
            		'relation' => 'or'
            	]
            )
        )
	);

	return $meta_boxes;
} );