View file is application\views\admin\estate\edit.php, you should detect lines based on option type. For example if you changing for TEXTAREA (long input) then line 162…

You can for example add class hide  into:

<div class=”form-group”>

So replace it with omething like that:

<?php if($this->session->userdata('username') != 'sandi' && $val_option->id == 73): ?>
<div class="form-group hide">
<?php else: ?>
<div class="form-group">
<?php endif; ?>

In this case only user with username sandi will see option 74 field when edit property in administration…