How to configure access to multiple projects in Tomcat?

Question

Java

I deployed several projects in Tomcat on a VPS, and also organized access through proxy_pass in Nginx, attached a domain to the VPS.
But I can not figure out how to organize separate access to projects. It is necessary that from one project there is no access to another, as well as that there is no access to Tomcat (roughly speaking, so that it is not visible at all).
Please tell me the best way to do it?