Hi Phoebe,
you could try and use a wrapper object around your DS retrieved list. The entity around your list then has the search information such as strings, references or whatever you like to search for in your DS retrieved list.
refreshing the search wrapper will force a new retrieve my microflow of your list. You then can make use of this by using your your search wrapper information (input by the user, whatever he wanted to search for) to limit your microflow search results (eg when using xpath)