Upvote:13
The industry term for what you're looking for is a suite, which typically means you get a separate living room and bedroom, although you need to do some due diligence: some hotels have single-room "studio suites". A one-bedroom suite is what you need.
Tripadvisor has a Suites filter under Amenities, and there's even a dedicated suites only search engine called Suiteness. That said, it's worth also looking into serviced apartments/Airbnb, which gets you a kitchen as well and are quite often more affordably priced.
Tripadvisor's Suites filter: