When you untar the aolserver source code it creates (for 3.0) a directory called aolserver3_0. Assuming that you untarred and built aolserver in /usr/local/aolserver, you would run the nsjava configure as follows:
./configure --with-aolserver-src=/usr/local/aolserver/aolserver3_0
The nsd.h file should be in /usr/local/aolserver/aolserver3_0/nsd for this example.
