ES aggregation Query clarification

Hi All,

I am trying to form an aggregation query to get the top document for an item, Since we have indexed a data as like this, A single item has been partitioned into multiple documents as like below,

Item:- 012312
Partitioned the item into multiple documents 012312_1, 012312_2 etc..

Below is the aggregation query,

GET /es_item/item/_search
{
"size": 0,
"aggs": {
"item_types": {
"terms": {
"field": "ITEM_ID"
}
}
}
}

The above query fetches the top 10 items from the overall indexed data and values are showing in desc order,

I want to pass a single item_id in the aggregation query and get the top document in desc order.

Please help us to get this.

Thanks,
Ganeshbabu R