Thanks for your revert.
We have validated your query. But using the keyword, we could not get the latitude and longitude values in the maps controls. For this scenario, you have to store the latitude and longitude values of a country or state or address to a keyword. Then in the sample level, from these names we can get the coordinates values and render the marker in desired position.
For your reference, according to the above discussion, we have prepared a simple sample with coordinates values for four countries in the dropdown list, which is having that corresponding country names. While we changing the country in dropdown list, it will return the latitude and longitude values to the marker dataSource. Attached the prepared sample in the below location.
Please let us know if you have any other concern.