I think it's an ordinary toolbar with 2 textfields inside UIView(which added as UIBarButtonItem to toolbar) to the top of the screen under the navigaionbar.
This is how I implemented it:
UIToolbar *bar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
UITextField *field1 = [[UITextField alloc] initWithFrame:CGRectMake(15, 5, 280, 30)];
UITextField *field2 = [[UITextField alloc] initWithFrame:CGRectMake(15, 50, 280, 30)];
[field1 setBorderStyle:UITextBorderStyleRoundedRect];
[field2 setBorderStyle:UITextBorderStyleRoundedRect];
UIView *viewForTextFields = [[UIView alloc] initWithFrame:bar.frame];
[viewForTextFields addSubview:field1];
[viewForTextFields addSubview:field2];
UIBarButtonItem *viewForTextFieldsBarItem = [[UIBarButtonItem alloc] initWithCustomView:viewForTextFields];
NSArray *items = [NSArray arrayWithObjects:viewForTextFieldsBarItem, nil];
[bar setItems:items];
[bar setContentMode:UIViewContentModeTopLeft];
[self.view addSubview:bar];