How to Implement “Add Related Item” Functionality in a Custom Action (Sales Order Line)

Hi Everyone,

I’m working on a customization where I need to add an action to the Sales Order line that behaves similar to the standard Add Related Item function. I already have a custom popup and a DAC that stores line-level kit component details. Now I want to extend this by adding the “Add Related Item” functionality inside my custom action.

I’m looking for guidance on the correct approach:

1. How can I call or reuse the existing “Add Related Item” logic from my custom action?

2. Is there a way to trigger the same popup and selection logic that Acumatica uses in the standard action?

3. If the standard behavior cannot be reused directly, what is the recommended pattern to rebuild this functionality for a custom grid action.

4. Any examples or references of extending or overriding the Add Related Item action would be helpful.

Screenshot to refer :
 

Thanks in advance for any suggestions or examples.