You can't nest custom tags like that; that's not a
Struts thing, that's just how
JSP works.
If you're running a JSP 2.0 container and the "aRoot" bean is in a
JEE scope just use JSP EL to access the property n the link tag. If you're not running a JSP 2.0 container use the Struts EL tag library, allowing you to use EL notation.