We can expand an associated ListItem from a DriveItem (i.e. /drives/{id}/root/children?$expand=listItem) to get the custom metadata columns.
We can search for specific keyword like:
groups/{{group_id}}/drives/{{drive_id}}/items/{{item_id}}/search(q='ABC')
But the search query will not return the custom metadata columns and we cannot expand the list item too from the search result (i.e. drives/{id}/root/search(q='{query}')?$expand=listItem).
We need the capability of expanding the list item on search result so we do not need to do the recursive calling again just to get the metadata columns.