In legacy Reports, I can filter very powerful, including "starts with", "contains one of", "advanced" etc.
In Workspace, the same feature only offers "contains" and "does not contain".
I wish that I'd have the full flexibility in Workspaces as well.
Good news! We just added a ton of these to Workspace last week. You now have everything that legacy Reports offers, and even a few more. The only one we don't have is the advanced special characters. We are considering adding a Regex feature in the future. But you should be much better off now.