How does this feature work- allow more than 1000 instances of this node in other tab in Subprocess

This is what you could do before. Nothing has changed, except that this is now a one-button configuration. And, wo answer your question, yes, this works.

Thanks for the quick reply. Can you also explain how it can be used for deleting more than 1000 Docs , we have call delete doc smart service inside the subprocess and pass list of docs to this subprocess

What do you mean with "how it can be used for deleting more than 1000 Docs"? Configure MNI on the Delete Document Smart Service.

If this is not the question, I need more details.

Yes Configured MNI on Delete document smart service and in the subprocess clicked on button to allow more than 1000 instances, after 1000 instances it failed.

Requirement is to delete more than 1000 docs .Please correct me here if is there anything i am doing wrong in this, 

Sorry, but I do not understand that sentence: "Yes Configured MNI on Delete document smart service and in the subprocess clicked on button to allow more than 1000 instances, after 1000 instances it failed."

I have no idea what you are doing and cannot see any of the objects you are working on. More details please!

Sure let me frame it this way how could we achieve the requirement to delete more than 1000 docs using MNI using Delete document smart service

That is exactly what I described a few posts earlier. Do you have any additional question?

You can not have more than 1000. Appian Process modeler will not allow you to do that. So, if you have more than 1000 in your array, you have to do deletion in batch (1000 in one batch) and a loop for it. Hope it helps. 

As described here

https://docs.appian.com/suite/help/22.4/Process_Node_and_Smart_Service_Properties.html#multiple-instances

you can run any number of sub processes.

So, in case you need to delete files, just put that delete document node in a sub process and run that process for each item in your list.