Vertical Alignment Tree (Used to be here)

Long story short...I'm back in the classroom after many years in Administration.  I used to have students work on Khan Academy and their was a tree dependency diagram or vertical alignment map. It was a WONDERFUL tool for students to understand WHY they were struggling with the current topic.  They could find the standard and see all the supporting standards listed as nodes below that topic. Students were able to identify what topics they should review before the lesson, AND could remediate themselves based on their self-assessment knowledge. Being placed in the "struggling math students" support role, I wanted to show students this tool only to not be able to find it.  Is there still such a tree out there in existence?  

Thanks,

Rodney