Property file:
Country[tab]City
United States[tab]San Francisco
United States[tab]Chicago
Mexico[tab]Mexico City
Mexico[tab]Cancun
Notice: tab key must be in between both level
Property File -> /var/lib/jenkins/workspace/ttt/parameter
Value -> Country,City
After above setting , multiple level multiple select can be used on dashboard of job
Multi-level Multi-select plugin
原文：http://www.cnblogs.com/root-wang/p/4512142.html