Sample comparison

Hi,

I want to compare stool samples microbiome which were collected at a different interval from the same participant, The study is to see the response dietary fibers on the microbiome. My question is, I want to compare alpha and beta diversity according to different intervals. How dietary fibers are affecting participants’ microbiome if they consumed the recommended diet during the study. I have tried different approaches but could not the desired result. The comparison I am getting is based on participants instead of intervals. I also followed the FMT tutorial but still not getting the result. Can you please help me?
https://view.qiime2.org/visualization/?type=html&src=fae7a772-b03c-4093-af6d-0db41650df93