Complex
$meta_query = array( array( array( 'key' => 'group_name', 'value' => 'Proflex 90', 'compare' => '=', ), ), array( 'relation' => 'OR', array( 'key' => 'group_value', 'value' => '7.2', 'compare' => 'LIKE', ), array( 'key' => 'group_value', 'value' => '8.6', 'compare' => 'LIKE', ), ), );