Select Servers > Server Types > WebSphere application servers > your application server > Class loader viewer service and select Enable service at server startup. Restart the application server for this change to take effect.
Navigating to Troubleshooting > Class loader viewer and then select the your WAR.
Expand Module - com.ibm.ws.classloader.CompoundClassLoader > Classpath to view the JAR files being loaded. Additionally, .class files below the "classes" directory will be loaded.
Selecting Classes will display the classes being loaded.
Likewise, if a JAR is deployed to a WebSphere application server, the classes in the JAR can also be seen at Troubleshooting > Class loader viewer, and then select the JAR file.