Usually the dropdown by default, filters the data based on the character
by character comparision as you type in. I do not think we have any
option to search a word in the list.The alternative approach would be
provide a text box for the user to type in and click on Search (Button).
Based on the search you can filter your array values and then populate
the dropdown. As you mentioned if you use the change event it will have
an overhead.ThanksSrini