Tableau integrates with R to offload the heavy lifting for statistical analysis. Theoretically...it's probably possible to connect to your decision tree.
I'm going to link you to a white paper and a video about R & Tableau. It's totally free. Once you sign in, there's a transcript at the bottom that you can download so you can skim through and see if this helps address the questions you have. (I prefer to skim through doc over watching a video, personally.) That said, the whole video's only 10 minutes, so it might be worth it for you.
Video: R Integration
Hope this helps!
Thank You. Will check it out