Addon “PlaceTool” from Kari Kujansuu simplifies place hierarchy import process. Import in Name and Title fields full hierarchy of a place and PlaceTool is able to generate the hierarchy after the csv file is imported to Gramps. The tool can resolve a hierarchy in ordinary or reversed order. You can also add a surrounding place to multi selected places in one sweep (or delete before that surrounding relation of all selected places.
I use PlaceTool all time in Isotammi project and warmly second it ! Thanks Kari, father of SuperTool also.