Shared maven/packages project

I cannot understand from docs if I can define a single maven enabled (aka packages) project within a private group shared (used by) many different CI built projects.

Let’s say that CI for ProjectA creates a libraryA.jar and ProjectB packages a war file which uses libraryA.jar as a dependency into it’s pom.xml.

AND how can I trigger ProjectB build when projectA is renewed?

BTW I’m using