Nesting tags is not permitted by the specification.
Some options would be:

• use a Runtime Expression (scriptlet) to obtain the second
  value


• write a new logic tag that accepts two beans


• enhance the functionality of your beans so that they do
  more of the work


• do the comparision in the Action and put the result in its
  own bean so the logic:equal tag can test a property

The last option would be the most often used.
The Struts architecture is based on the idea that most of the
processing will occur in the Action so that there is very
little left for the JavaServer Page to do, except output
HTML.

HTH -Ted