Drop the ArangoDB JAR(s) in the LISA_HOME/hotdeploy.
Research the ArangoDB documentation and determine which classes are required to execute a query.
Set up a JSR-223 step with the code to execute the query.
For Splunk, there are several classes that are used.
com.splunk.ServiceArgs // use this to setup user name, password, host machine and port
com.splunk.Service // use this to connect, login, and execute a query
com.splunk.ResultsReaderXml // use this to Iterate the results of a Service.oneshotSearch call
com.splunk.Job // might be used as well
com.splunk.JobArgs
You need to figure out which classes and methods are called for an ArangoDB and see if you can get it to work.