Really challenging to do this as you can filter on Smart Lists in MA but cannot specify a filter for "contains form trigger or filter". Another option, though not as fast, is to go into the Design Studio and look at the "Used By" section of every form you have. In that view, you will be able to see all smart lists that are using the form as a filter. Again, not very fast but not sure there is an easier way to locate all smart lists using the Filled Out Form is Any Filter.
This method does however ensure you are only looking at smart lists that have a form filter as opposed to having to audit every smart list you have in your instance. This job sounds like a great opportunity for an intern if you have one.
Wish there was an easier method, but really isn't.
On that note can you please explain why you are interested in locating these smart lists? Just for fun? What are you trying to accomplish? There may be other solutions than what you think you need to do here is why I ask.
Thank you for the reply. We have a really old instances of Marketo dating back to 2010. I am trying to get a list of active campaigns that contain a form. I can isolate on Form name or Form Id but there are a lot of programs out there where the SL is JUST; if "Form is any". We are switching from Marketo forms to website forms. In order to prepare a website-to-API script I need a list of active campaigns where a form fill is part of the SL.