Just FYI, it is Liquibase without the d in the middle - makes for better searchability if everyone uses the correct name,
I am not familiar with elasticsearch, but it seems to me that if it is dependent on the data in another database, you should come up with a solution that periodically scans the database and updates elasticsearch rather than tying your application code to two different data sources.
If you want to alter how Liquibase works, you would need to write custom code to do that. You would probably want to look at creating your own change type that is similar to the LoadDataChange class, but that also updates elasticSearch.
Principal Software Engineer
Datical, Inc. http://www.datical.com/