Using Grove Seed Ultrasonic sensor with Raspberry Pi without the Grove Base Hat

Would it be possible to use the Ultrasonic sensor without the Grove Base Hat, connecting it directly to a Raspberry Pi ?

Are you talking about the HCSR-04 SONAR sensor? If yes, then you can use the ultrasonic sensor without the Grove-base hat. You have to use four female to female jumpers.

I was actually referring to the ultrasonic Grove Ranger sensor. Are they one and the same ?

This one,right? Grove - Ultrasonic Ranger - Seeed Wiki
This one comes with a 4-pin connector cable. You will have to connect 4 Male to Female jumpers with the connecting cable. The female sides with go to Raspberry Pi.