Hi Carmen,
I’ve not done it in excel, but you can also customize your taxa barplot in R. You can import your metadata, feature table and taxonomy into R following the qiime2R tutorial. There’s another R package, MicrobeR, developed by the same author, which allows you to make grouped taxa barplot using the imported data.
I also wrote an R function based on the MicrobeR pakcage, which allows you to quickly make publication-quality taxa barplots. If you’re interested, check the code I used for my project.