"from the same group" is correct and usable in written English.
You can use it when referring to a group of people who have something in common. For example, "We all come from the same group of alumni."
Officials declined to say whether the three suspects were from the same group.
They say, 'Now we do another bag from the same group?' I said, Forget the groups!
From the same group as the Carmarthen Journal and the Llanelli Star.
Most Justices draw their clerks from the same group of appellate court judges.
Three newspapers from the same group have just closed their doors.
At Senter point we found more tracks, most likely from the same group of wolves.
They also said that he was involved in an earlier gun buy that the detectives made from the same group.
In 2009, another seminal paper from the same group showed that cleaning up air pollution increased life expectancy.
Things eventually calmed down, and a young veiled woman — from the same group of friends — posed another question.
Just over a third (36%) of John Lewis's customers and 34% of House of Fraser's come from the same group.
When and, (10) represents CCF of two sequences from the same group, namely, intragroup CCF.
