Feature coming in the next release. Let's start simple, with a checkbox that allows you to show only "NOT OK".
In a 2.0 or further, it would be great if we had a way to filter by status and directive. For example, NOT OK and TODO.
You will have to trigger a new build to apply the filter (part of this happens in the server side). But we can also re-think in the future, in a client-side solution. Though if we want to support a lot of tests, that's probably not a good idea.
Thanks for reporting, and sorry for taking so long to reply.
Give it a try, let us know if that worked, and let's continue refining the code. The next releases are bugfixes, but we will have a 2.0, probably this year, focused in performance and polish the code.