Hi Gary. Afaik, none of the NIK Suite leave any metadata changes. Because of that, the best you can do is filter for Images that have been edited by an external editor. This is a poor proxy, of course: it includes Images edited by _any_ external editor, and not just one of the NIK Suite.
I created keywords for all of my plug-ins, and have tried to make a habit of applying the keyword once the Image is returned to Aperture. Here is my list of keywords for the NIK Suite:
Do you use PS? You can set PS as your external editor, and use (if you have them) the NIK Suite PS plug-ins. If you set Aperture to create PSD files, and don't flatten your files in PS, then you can re-open the "quasi-Original" in PS and see (and make changes to) the NIK tool(s) used. Note that PSD files are huge compared to flattened TIFFs.
I think Aperture should keyword every Image with the name of any plug-in or external editor used. If you agree, please let Apple know, via "Aperture➞Provide Aperture Feedback". Thanks.
I've got to read up on Keywords, Filters, Making a Filter Preset (with a unique name).
And right now, I'll venture over to the Aperture feedback webpage and make an appeal. Gosh, I wish there was a book on Aperture. Lots to learn.
There is. It is very powerful and full-featured, and somewhat misleadingly stream-lined.
The first thing to do is familiarize yourself with the interface and learn what the major parts (Project, Image, Version, Original, Folder, Album, Smart Album) are and do.
Here are some helpful links. While it may seem round-about, you will become adept sooner if you create a test Library and use it to try out everything.
There are no "filter presets". That function is met by Smart Albums.