How to set a field editable only for a group? In odoo9
<p>In hr attendances, there is a field called "employee_id".</p>

<p>I want to set this field editable only for a group (or set readonly for other groups).</p>

<p>For example, I want to set the field "employee_id" editable in the "form" view only for the "manager" group.</p>

<p>I have extended the attendance module and I have this code in the XML of my extended module:</p>

<pre class="lang-xml prettyprint-override"><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;openerp&gt;
    &lt;data&gt;
    &lt;record id="view_employee_readonly_custom" model="ir.ui.view"&gt;
        &lt;field name="name"&gt;hr.attendance.form&lt;/field&gt;
        &lt;field name="model"&gt;hr.attendance&lt;/field&gt;
        &lt;field name="inherit_id" ref="hr_attendance.view_attendance_form"/&gt;
        &lt;field name="groups_id" eval="[(6,0,[ref('base.group_hr_manager')])]"/&gt;
        &lt;field name="arch" type="xml"&gt;
            &lt;field name="employee_id" position="attributes"&gt;
                &lt;attribute name="readonly"&gt;True&lt;/attribute&gt;
            &lt;/field&gt;
        &lt;/field&gt;
    &lt;/record&gt;
    &lt;/data&gt;
&lt;/openerp&gt;
</code></pre>

<p>With this code, the field is editable for everyone EXCEPT for the hr_manager group. That is the opposite that I want.</p>

<p>What I have to modify in order to achieve this?</p>

<p>Edited: I have modified the original code with a different field to better understanding.</p>