title: hide button according to group
body: <p>I have a defined groups and i want to display a button according a group.</p>
  
  <pre><code>&lt;button name="assign_ticket" states= "pending_assignment,draft" groups="group_centricare_care_agents" string="Assign to me"/&gt;
  </code></pre>
  
  <p>i want this button to be displayed to the group "roup_centricare_care_agents" but when adding groups tag it cause an exception.</p>
  
  <p>P.S.: This button in tree view.</p>
  
  <p>How can i do this??</p>
  
  <p>Thanks in advance</p>