I have tested René Schuster's solution on latest version openerp and it works:
<field name="name" filter_domain="['|','|',('name','=ilike',self+'%'),('parent_id','=ilike',self+'%'),('ref','=',self)]"></field>
it sends correct request ang get correct result
POST DATA:
{"jsonrpc":"2.0","method":"call","params":{"model":"res.partner","fields":["sale_order_count","title","parent_id","street","country_id","email","street2","state_id","display_name","zip","color","city","opportunity_count","function","phone","has_image","is_company","meeting_count","mobile","category_id","__last_update"],"domain":["|","|",["name","=ilike","a%"],["parent_id","=ilike","a%"],["ref","=","a"]],"context":{"lang":"ru_RU","tz":"Asia/Yekaterinburg","uid":1},"offset":0,"limit":40,"sort":""},"id":903990513}
It returns only contacts starting with "a".
So, the solution is to modify base.view_res_partner_filter view with filter_domain above
Bogus answer. i accidentally clicked on "Convert to answer" on a comment (that wasn't even mine!) and I can't find a way to delete this answer.
In search box, click on little down arrow and open full search menu. Select advanced search, choice name beginnig with Antonio Maria Vigliotti
Sorry, Leonardo is right. There is no option "beginning with" in advanced search