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;
} );