What is a drop-down list with search suggestions?
A search suggest drop-down list is a query feature used in computing to show the searcher shortcuts, while the query is typed into a text box. Before the query is complete, a drop-down list with the suggested completions appears to provide options to select.
How do I enable search in Data Validation list?
How to Search Data Validation Lists. With the new update, you can now type your search directly in the cell that contains the dropdown list. A list of results will appear that match your search term. You can select a result with your mouse or use the arrow keys and press Enter.