Q: Need to locate the files under "Other" in HD useage?

“Other” storage: https://support.apple.com/en-us/HT202867

User tip on “other” https://discussions.apple.com/docs/DOC-5142

Also, it is a possibility that the numbers shown are wrong. If so, re-indexing may correct that: https://support.apple.com/en-us/HT201716

In addition to FoxFifth's good advice, Omni DiskSweeper can show you the precise size and location of all your files. It will inventory your disk starting from the files that take up the most space. It can also give you a more accurate read of disk space than Finder or Storage Tab of About this Mac. If you want you can even delete files from OmniDisk Sweeper.