Nested views in openerp

I'm trying to show a field in the tree view not referenced directly in the object fields, in my case stock.picking. The field I'm trying to show is referenced by other referenced field, in my case:

stock.pinking -> address_id -> partner_id -> payment_days.

And I've modify the xml view adding:

<field name="address_id">
  <tree>
     <field name="partner_id">
       <开发者_开发百科;tree>
         <field name="payment_days"></field>
       </tree>
     </field>
  </tree>
</field>

But this view only show the partner_id, doesn't complaint about the payment_days, but it doesn't show it... Is it possible to show it?

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As far as I know, OpenERP will just ignore that nested tree tag. To display a field from a related table in a tree view, I think you have to add it to the main table as a related field and then display it in the view.