---
title: Bucket selector aggregation context
description: Use a Painless script in an bucket_selector aggregation to determine if a bucket should be retained or filtered out. The standard Painless API is available...
url: https://www.elastic.co/docs/reference/scripting-languages/painless/painless-bucket-selector-agg-context
products:
  - Elasticsearch
  - Painless
applies_to:
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
---

# Bucket selector aggregation context
Use a Painless script in an [`bucket_selector` aggregation](https://www.elastic.co/docs/reference/aggregations/search-aggregations-pipeline-bucket-selector-aggregation) to determine if a bucket should be retained or filtered out.

## Variables

<definitions>
  <definition term="params (Map, read-only)">
    User-defined parameters passed in as part of the query. The parameters include values defined as part of the `buckets_path`.
  </definition>
</definitions>


## Return

<definitions>
  <definition term="boolean">
    True if the bucket should be retained, false if the bucket should be filtered out.
  </definition>
</definitions>


## API

The standard [Painless API](https://www.elastic.co/guide/en/elasticsearch/painless/current/painless-api-reference-shared.html) is available.

## Example

To run the example, first [install the eCommerce sample data](/docs/reference/scripting-languages/painless/painless-context-examples#painless-sample-data-install).
The following request filters out low-performing manufacturers and focuses only on brands with significant sales volume. The query groups orders by manufacturer, counts total orders for each brand, then uses a bucket selector to show only manufacturers with 50 or more orders.
```json
GET kibana_sample_data_ecommerce/_search
{
  "size": 0,
  "aggs": {
    "manufacturers": {
      "terms": {
        "field": "manufacturer.keyword"
      },
      "aggs": {
        "total_orders": {
          "value_count": {
            "field": "order_id"
          }
        },
        "high_volume_filter": {
          "bucket_selector": {
            "buckets_path": {
              "order_count": "total_orders"
            },
            "script": {
              "source": "params.order_count >= 50"
            }
          }
        }
      }
    }
  }
}
```