Search Option in the Dropdown Item List

[shahappsheet]

Hi Guys! Hope all of you are great.

I want to include a search option on the dropdown selection list using Ref. There is a demo app. But I couldn’t find out how it was done. In the demo only for 4 items the search option appear but for my case the search option appears after the list becoming long. Would any one please get some explanation in this regard.

Thanks.