Find valid entries in a range and list each valid entry

I am trying to create a worksheet that looks up valid entries in a database and report those entries that match a particular criterion. Specifically, I have fields in an excel worksheet for first name, last name, grade level, and instructor for each of several individuals. I would like to list all those individuals (and only those individuals) on a separate sheet that match for a particular instructor. I have used the index and match formulas toward accomplishing this task, but it doesn't quite work the way I'd like it to. Any suggestions for a solution that will accomplish this would be much appreciated.