sql statement construction with unique group

I have a table that looks like this:

group | student ID | Date
1       1            2018-05-16:03:01
1       3            2018-05-16:03:01
1       2            2018-05-16:03:01
2       1            2018-05-16:03:01
2       5            2018-05-16:03:01
2       7            2018-05-16:03:01
1       9            2018-05-16:03:01
1       2            2018-05-16:03:02
3       2            2018-05-16:03:02
1       1            2018-05-16:03:02
1       1            2018-05-16:03:02

This is to track which group with student ID in the lab, ordered by Date desc

Let's say if I want to get the latest unique group's student who were in the lab within the past 1 hour, how would I select it? so the result would be

group | student ID | Date
1       1            2018-05-16:03:01
1       3            2018-05-16:03:01
1       2            2018-05-16:03:01
2       1            2018-05-16:03:01
2       5            2018-05-16:03:01
2       7            2018-05-16:03:01
3       2            2018-05-16:03:02