---
url: /process-functions/hierarchy-descendants.md
description: Returns the leaf elements below a parent element in a hierarchy.
---

# hierarchy.descendants

Returns the leaf elements below a parent element in a hierarchy, at every level. Parent elements along the way aren't included.

```js
hierarchy.descendants(dimension, hierarchy, parent)
```

## Parameters

| Parameter | Type | Description |
|---|---|---|
| `dimension` | `string` | The dimension's name or id. |
| `hierarchy` | `string` | The hierarchy's name or id. |
| `parent` | `string` | The parent element's name. |

## Returns

The names of the leaf elements as a JSON string. Read it with `JSON.parse()`. A leaf that sits under more than one branch is listed once for each. Returns `null` when the dimension, hierarchy or element can't be found.

## Examples

```js
const elements = JSON.parse(hierarchy.descendants("Time", "Days Since Release", "Days Since Release"));
```