search for: 500x5

I can think of several ways to blunt force hard code what I want but I imagine there is a command or two that can be easily combined to do this: I have a data frame with about 23000 observations. There first variable is the group to which the observation belongs (about 500 different groups). The second variable is a response for each observation that is a 1,2,3,4 or 5. I want to be able to