Not sure how you are working with the Viewer? Tag references or Application Builder? Either way you should be able to do this. If working in Application Builder, all you would need to do is check on the dialog box "Add result as operational layer" in the Search widget settings. This does the equivalent of the <shareresults> tag in the Search Widget config tags, http://resources.arcgis.com/en/help/flex-viewer/concepts/index.html#/Search_widget_tags/01m300000023....