Você pode usar a seguinte consulta:
SELECT ID, brandname, cdt, udt, brandstatus, addedby
FROM (
SELECT ID, brandname, cdt, udt, brandstatus, addedby,
ROW_NUMBER() OVER (PARTITION BY brandname,
CAST(udt AS DATE),
CONVERT(VARCHAR(5), udt, 114)
ORDER BY udt DESC) AS rn
FROM brands) AS t
WHERE t.rn = 1
Esta parte:
CONVERT(VARCHAR(5), udt, 114)
é usado para extrair hora e minuto de
udt
campo.