Filters the loaded AttrTree using the supplied path_filters.

def filter(self, path_filters):
        """
        Filters the loaded AttrTree using the supplied path_filters.
        """
        if not path_filters: return self

        # Convert string path filters
        path_filters = [tuple(pf.split('.')) if not isinstance(pf, tuple)
                        else pf for pf in path_filters]

        # Search for substring matches between paths and path filters
        new_attrtree = self.__class__()
        for path, item in self.data.items():
            if any([all([subpath in path for subpath in pf]) for pf in path_filters]):
                new_attrtree.set_path(path, item)

        return new_attrtree