code: func (p RootPathParticle) SplitRelativeFolder(inventoryPath string) (string, error) {
  	relative, err := p.SplitRelative(inventoryPath)
  	if err != nil {
  		return inventoryPath, err
  	}
  	return path.Dir(relative), nil
  }
docs: // SplitRelativeFolder is a convenience method that returns the parent folder
  // for the result of SplitRelative on the supplied path.
  //
  // This is generally useful to get the folder for a managed entity, versus getting a full relative path. If you want that, use SplitRelative instead.