Adding two comboboxitems to filterbuilder which gives rendering issue

I am trying to add one more comboboxitem to filterbuilder using canvasitem. i am adding two comboboxitems to dynamicform and this form is adding to canvasitem. this canvas item is set to filterbuilder. It displaying first time its fine. but when i am
clicking add button or clause button , the component itself moving to other location. see the below code

FilterBuilder testBuilder = new FilterBuilder();
testBuilder.setBorder("1px solid red");
testBuilder.setDataSource(new DataSource());

SelectItem fieldNameItem1 = new SelectItem();
fieldNameItem1.setWidth(200);

SelectItem fieldNameItem2 = new SelectItem();
fieldNameItem2.setWidth(200);

DynamicForm dynamicForm = new DynamicForm();
dynamicForm.setWidth(100);
dynamicForm.setFields(fieldNameItem1,fieldNameItem 2);


SelectItem fieldNameItem = new SelectItem();
fieldNameItem.setWidth(200);

CanvasItem canvasItem = new CanvasItem();
canvasItem.setCanvas(dynamicForm);

testBuilder.setFieldPickerProperties(canvasItem);
testBuilder.draw();

i am attaching screen shot. where i am doing wrong? or is it support in filterbuilder?

Regards
Pandu

Attached Images

FB.png (62.8 KB)