# AddNestedQueryAggregator<TNestedQueryData>(string, Func<IEnumerable<TNestedQueryData>, IEnumerable<TNestedQueryData>>)

> Adds a new nested query aggregator. An aggregator is an operation that can be applied on a nested query to aggregate the results of the nested query according to certain criteria.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.Search](/engine/6000.7/script-reference/unityeditor/search.md)
* **Assembly:** UnityEditor

## AddNestedQueryAggregator\<T>(string, Func\<IEnumerable\<T>, IEnumerable\<T>>)

```csharp
public void AddNestedQueryAggregator<TNestedQueryData>(string token, Func<IEnumerable<TNestedQueryData>, IEnumerable<TNestedQueryData>> aggregator)
```

### Parameters

**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): Name of the aggregator used when typing the query. This name is converted to lowercase when parsing the query to speed up the process.**** (\[Func\<IEnumerable\<T>, IEnumerable\<T>>]\(https\://learn.microsoft.com/dotnet/api/system.func-1)): Aggregator function. Takes the results of the nested query, and returns an aggregate that contains any number of items.

### Remarks

\\\<typeparam name="TNestedQueryData"\\>The type of data returned by the nested query.\\\</typeparam\\>