Converts filter_path to a path on the child model of filter. That is,
filter_path points to a location in filter. The returned path will
point to the same location in the model not being filtered. If filter_path
does not point to a location in the child model, NULL is returned.
Converts filter_path to a path on the child model of filter. That is, filter_path points to a location in filter. The returned path will point to the same location in the model not being filtered. If filter_path does not point to a location in the child model, NULL is returned.