The below input field only showing 5 values in dropdown and no auto complete box. I can see it try to show all fields initially and at the end of the search it just showing 5 values + default value and this is not the case all the time. Some times it is not showing anything other than default value.
Values of both attribute points to a field in the search result (search result field specified in fieldForLabel will be shown as labels in dropdown and field specified in fieldForValue will be used as value for corresponding label). You search query has just env_name and count as field, so fieldForLabel is wrong here. Try this