Extendible Hashing Repointing Pointers After Directory Doubling

Question

I need to understand the rules of re-pointing the pointers once the directory has doubled. Each bucket will have two times its current pointers, but my question is how to determine which of the directory entries to point to each of the buckets? Note: this is not a question of re-pointing the pointers after a bucket split in which local depth is lower than the current amount of bits used in the directory, in which the bit at local depth+1 would determine this.