insert page title as :before pseudo element content

I thought I might be able to use the existing page title tag for header elements when setting this up, but it isn't working. How do I go about inserting the respective page title as the content. Here's what I'm after: https://www.screencast.com/t/prvGV8Lk51l

1. I'm adding a :before pseudo element to the page hero H1
2. Here's the end result I'm after
3. I need to know what to use for the content value

Many thanks!