# CDP Pipeline: Overview of Pre-Defined Filters in Destinations
### Introduction
This feature helps you find and remove duplicate records in your **Destination**. This functionality is available in pipeline.
### Follow These Steps to Remove Duplicate Records from Your Pipeline:
**Step 1:** In the navigation panel, click **Pipeline**.
**Step 2:** A list of pipelines appears. Click the pipeline you wish to open.
**Step 3:** Click **Destinations**.
**Step 4:** Click on **Add Destination**.
**Step 5:** The Destinations panel opens on the right side. Click **Select Destination.**
**Step 6:** The Select Destination panel opens. Use the search bar to find a destination, select one from the list, or create a new destination by clicking Create Destination.
**Step 7:** Click on Filter.
**Step 8:** Check the **Enable Filter** box.
**Step 8:** When you check the box, the Function tab will open.
Under the Type dropdown, select **Pre Defined Fn**.
**Predefined Functions:** Built-in system functions with standard logic that require no customization.
**Step 8.1:** In the **Select Function Typ**e dropdown, select **Event Deduplication**.
**Step 8.2:** **Additional Arguments** will open. In the **Event Namespace**, select the value from the corresponding **Value** dropdown, or you can enter a value manually.
In the **Deduplication ID**, select the appropriate value from the corresponding **Value** dropdown, or you can enter a value manually.
**Step 9:** Click **Custom Fn**
**Custom Functions:** User-defined functions that allow customization based on specific requirements.
**Step 9.1**: Function Arguments: To configure function arguments, follow these steps:
**Step: 9.2: Enter a Name** in the **Name** field to define the function argument.
**Step: 9.3:** Click on the **Data Source Field** tab. A list of available data source fields appears on the right side. Select the appropriate **Data Source Field** from the list.
**Step 9.4**: Code
In this tab, you can write custom code for the function. After writing the code, click the **Test Function** button to execute and validate the function.
**Step 10:** Click **Save**.
