I'm using the REST API (via a web app) to search a users's content for a specific type of content (KML files)
https://portalserver/gis/sharing/rest/content/users/arcgisadmin/?types=KML returns no items, because there are no KML items in the root folder
https://portalserver/gis/sharing/rest/content/users/arcgisadmin/ec638ccb4d8e44c0b0fe9910d989afb2?typ... returns some items because the user uploaded some KML files to this folder
However, what is a user has 30 folders - I don't want to make 30 requests.
The base request is
https://portalserver/gis/sharing/rest/content/users/arcgisadmin?types=KML&sortField=&sortOrder=&fold...
GUI is here....

I could not find in the documentation anything about Include Folders List (folders param in the GET request) or Include Folders Content (foldersContent in the GET request).
Can I use these to search all the users content to get all KML files instead of having to individually search each folder? Can someone point me to the documentation on how to use them?
Thanks!