This is a container clue - one word or phrase goes inside another word to form the answer.
Look for a word meaning 'centre' that can contain a word meaning 'unwarranted' or 'over-the-top'. The containing word should relate to a central place or hub.
Answer: HOT TUB | HUB (centre) contains OTT (over-the-top, unwarranted) to give H-OTT-UB = HOT TUB (bath)