I have used this for a custom taxonomy but it doesn't seem to be working, anything I am clearly doing wrong or anything I need to include?
'name' => 'Off Market Property?',
'id' => self::$prefix . 'off_market',
'type' => 'checkbox',
'tab' => 'general',
'visible' => array( 'slug:tax_query[_property_destinations]', 'in', array(7,9) ),