In Chrome, navigate to your Steam Workshop subscriptions page for the game you want to export.You need the text inside the file, not the file. Copy the source code contents of SWSSrape.js below.Open Chrome (I haven't tested in any other browser so you're on your own trying others).It's expected that you already know how to use the JavaScript console in the Chrome web browser. So I made this little monstrosity over an evening.
Unfortunately Vavle/Steam doesn't do such a thing natively and I had to get really creative for my list of several hundred items so I could share with a friend.
This is just something I whipped up to dump a listing of my own subscriptions for a particular game. Steam Workshop Subscriptions Scraper Description