iAssets: Create an Asset List - can I merge list results into one list?

We use Oracle iAssets (12.1.3) and there's functionality when doing a search to Create a List. And you can save your results.

But if you come back later and want to add more results to that saved list, I do not see any option to do so --- you can only create yet another new list.

Does anyone know if it's possible to save to an existing list instead of creating a new list each time? Or can results be merged?

Thanks!

ps for what I'm talking about, the topic is in the iAssets User Guide in section 3-2 (pg 28), but it's extremely brief.