This doesn’t directly match a common phrase or known code, but it has the structure of a (each hyphenated chunk could be a word).
To “complete the feature,” the most probable full phrase would be: thmyl-ttbyq-layk-stwry
Forward ROT-1: t→u, h→i, m→n, y→z, l→m → uinzm (no). Given the symmetry of the groups (5 letters each), maybe it’s a encoded by a simple cipher. But without a key, best guess: This is likely from an ARG or puzzle where the solution phrase is “The mystery lake story” or “The Mill by the Lake Story” — but incomplete. This doesn’t directly match a common phrase or
It looks like you’ve provided a string of letters and hyphens: thmyl-ttbyq-layk-stwry