Start by opening terminal and going into the "/Applications/Server.app/Contents/ServerRoot/usr/sbin/" directory.
Then, run the following (it's a long one, mind the newline):
./named-compilezone -f raw -F text -o /path/to/your_output_filename.txt your_zone_name.com /Library/Server/named/db.your_zone_name.com
Where "your_zone_name.com" is the name of your dns zone, and "/path/to/your_output_filename.txt" is the path to the output file you'd like the data written to. After you run the command, you can open the output file in any text editor and see the contents.