Hello Gobman,

@Bole is 100 % correct,here we use name_get method for custom many2one field

here i give one example of name get_method hope this code is very help full

class hobbies_hobbies(osv.osv):
    _name = 'hobbies.hobbies'
    _columns = {
        'name' : fields.char('Hobby Name'),
        'place' : fields.char('Place'),
        'code' : fields.char('Code'),
    }
    
    def name_get(self, cr, uid, ids, context=None):
        res = super(hobbies_hobbies, self).name_get(cr, uid, ids, context=context)
        final_result = []
        if ids:
            for hobbies in self.browse(cr, uid, ids,context=context):
                hobbies_data = hobbies.name or ""
                hobbies_data += " ["
                hobbies_data += hobbies.code or ""
                hobbies_data += "] "
                final_result.append((hobbies.id, hobbies_data))
            return final_result
        else: 
            return res

if you find this answer helpful, please give me a thumbs up vote    

Regards,

Ankit H Gandhi

in your new object you need the result of  _name_get method.

by default _name_get will show field name 
if some other field shoud be used for representing name, then you define it in _rec_name = 'other_field'
and if you want name to be shown as combination of few field values then you need to define 
_name_get method

all this should be done in py file defining the object.... 
hope it helps...