Another solution to retrieve the previous options that I found and can be used with the actual forge version is to split the CommandCompleterState.getBuffer() and find the next value in the String array. Something similar to:

String[] splitedCommand = state.getBuffer().split("[\\s]++");
//find the option in splitedCommand
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators.
For more information on JIRA, see: http://www.atlassian.com/software/jira