This directory is found in in the unpacked content files (Wii U version only). Its canonical path is "Local".
Local appears to be a development remnant. It is unused in release versions and is not present at all on Switch.
Note that because this directory does not actually exist, the following list might be incomplete.
Identical to the regular System/RegionLangMask.txt on Wii U.
Analysis of the executable reveals that during development, ActorInfo.product.byml is loaded from Local/ActorInfo.product.byml.
In release versions, the game will still load from Local if a debug heap is present in the init parameters (sead::Heap* at offset 0x8) or if a flag is set in the GameConfig structure (bool at offset 0x3d0).
- The check is located at 0x7100F3B694 in Switch 1.5.0