Configure domain of JSESSIONID cookie on JBoss

Issue

• Is there a way to configure the domain of the JSESSIONID cookie sent by JBoss/Tomcat?
• When using <SessionCookie path="/test" secure="true" httpOnly="true" domain="test"/> what does the (domain="") used for?
• We are in the process of migration from EAP 4 to EAP 6. We can't find equivalent files (context.xml etc) to set the cookie which can be shared across subdomains.