type ParseUrlParams<Url> = Url extends `${infer Start}/${infer Rest}`
  ? ParseUrlParams<Start> & ParseUrlParams<Rest>
  : Url extends `{${infer Param}}`
    ? { [P in Param]: string }
    : {};

function navigate<P extends string>(path: P, params: ParseUrlParams<P>) {
  // ...
}

function main() {
  navigate("/foo/bar", { foo: "asd" });
}