"Parse HTML" button missing in SharePoint Designer 2010

I am trying to follow along with this question to Group By more than 2 levels in a View. The problem is, every tutorial starts with "Click Parse HTML" under Code Editor. I don’t have a "Parse HTML" button, as you can see here:

I’ve gone through all the Ribbon settings and it’s just not there. Is there a setting I’m not familiar with causing it to be hidden? Thanks in advance for any help.