return latest row on specified record types

Basically what I am trying to get it a single row for each record where workflow is published and the latest valid_to date.. Some numbers will also have a workflow of draft and null and I still want those to return with their valid_to date as will the latest workflow of Published . The only ones that need to be filters down to one row is the ones with workflow published.. I am attaching a sample workbook with some sample data.

I know I'm prob missing one single step but any help would be appreciated.

Thanks,

--Brian