Roma Sotterranea Underground Tours

https://www.visiteromasotterranea.it/il-ghetto-ebraico-di-roma.html

Rome Sotteranea Tours gives you the chance to see Rome's unusual and (literally) hidden sights - the ones underneath the buildings and streets and parks of the city. Archeological areas below the surface, crypts, catacombs, and below the fountains are just some of the tours they offer guided walks through little-known areas and neighborhoods, like the Jewish Ghetto, below many churches (like San Martino ai Monti, pictured) and extraordinary openings of places that are often closed to the public. Check their website for details! You'll find a lot to choose from!

Note - their office is in the EUR district but their tours are conducted throughout central Rome and beyond. The site can be a bit tricky to navigate but the sidebar on the right side is where you'll find most of the tours by area of interest. They have a contact form on the site, for your questions.