After making the video, I found that there is a way to have variables for your entire document, contrary to what I've said in this video! On the bottom navigation bar, press the [+] symbol and hit "Create Variable Studio". In here, you can create variables that can be used on the entire document! To easily view these when working on a document, press the "Variable Table" symbol at the right edge of the window. I've updated the Document with these changes. Hope this helps!