function old() not allow input name type array

Hi.

PHP Code:

<input id="meta[full_name]" name="meta[full_name]" placeholder="Full name" value="<?= old('meta[full_name]'); ?>" type="text" class="form-control "> 


After post, it not store old input data from form, because it store in $_SESSION['_ci_old_input']['post'] type array.

How to get old data from input name type array.
Thanks all