# customDefinition

> The custom filter function definition, when the filter function type is FilterFunctionType.Custom.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine.UIElements](/engine/6000.7/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
public FilterFunctionDefinition customDefinition { get; set; }
```