I have successfully added sale_name in the edit treeview

 <field name="sale_name"/>

but when I try to add sale_name in the edit searchviewwith:

<filter string="Sale Name" icon="terp-accessories-archiver" domain="[]" context="{'group_by':'sale_name'}"/>

I get this error:

Client Traceback (most recent call last): File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\http.py", line 204, in dispatch File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\controllers\main.py", line 1125, in call_kw File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\controllers\main.py", line 1117, in _call_kw File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\session.py", line 42, in proxy File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\session.py", line 30, in proxy_method File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\session.py", line 103, in send Server Traceback (most recent call last): File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server\openerp\addons\web\session.py", line 89, in send File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\netsvc.py", line 292, in dispatch_rpc File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\service\web_services.py", line 626, in dispatch File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\osv\osv.py", line 190, in execute_kw File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\osv\osv.py", line 132, in wrapper File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\osv\osv.py", line 199, in execute File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\osv\osv.py", line 187, in execute_cr File "C:\Program Files (x86)\OpenERP 7.0-20140122-002452\Server\server.\openerp\osv\orm.py", line 2647, in read_group AssertionError: Fields in 'groupby' must be regular database-persisted fields (no function or related fields), or function fields with store=True