# GroupOnContext

> _Since v3.9.0_

Second argument passed to GroupingRowsConfig.groupOn.

Grouping applies to every list of sibling rows. Without TreePlugin there is
only the root list (`parent: null`, `depth: 0`); with TreePlugin the
children of every expanded tree node form their own list.

## Properties

| Property | Type | Description |
| -------- | ---- | ----------- |
| <span id="parent"></span>`parent` | <code>any</code> | The tree row whose children are being grouped, or `null` for the root rows. |
| <span id="depth"></span>`depth` | <code>number</code> | Nesting depth of the rows being grouped (0 = root rows). |