Dear xoomserve,
Here is the example which I've created with Meta Box Builder:
add_filter( 'rwmb_meta_boxes', 'your_prefix_register_meta_boxes' );
function your_prefix_register_meta_boxes( $meta_boxes ) {
$meta_boxes[] = array (
'id' => 'untitled-metabox-2',
'title' => 'Untitled Metabox',
'pages' => array (
'post',
'page',
),
'context' => 'normal',
'priority' => 'high',
'autosave' => false,
'fields' => array (
array (
'id' => 'properties',
'type' => 'taxonomy',
'name' => 'Properties',
'taxonomy' => 'product_type',
'field_type' => 'select',
),
array (
'id' => 'another_text_field',
'type' => 'text',
'name' => 'Text Field',
'visible' => array (
'when' => array (
array (
'taxonomy_2',
'=',
'4',
),
),
'relation' => 'and',
),
),
),
);
return $meta_boxes;
}
Basically, you can register your taxonomy field and another field normally. And then, in related field (Text in this example), just define your conditional logic:
'visible' => ['your_taxonomy_id', '=', 'taxonomy_value']