Set a Root folder in embeded document library portlet

Development
1

Hi I’m Trying to set the root folder id of a embeded document library portlet but its always setting home folder as root folder
<liferay-portlet:runtime
portletName=“com_liferay_document_library_web_portlet_DLPortlet”
instanceId=“<%= dlInstanceId %>”
/>
i have tried default prefrences and set the prefrences but the value is not shown in the UI.

Thanks,

Srikanth