I don’t see a sure shot easy way to do this. Here are some options to try:
Option1: Use these Manual upgrade steps
See: https://bahmni.atlassian.net/wiki/spaces/BAH/pages/103350284/Upgrade+to+Latest+Bahmni+Release (Section: Upgrade to Bahmni 0.92)
Here, you are backing up all existing DBs (and files) and restoring them as-is for new Bahmni. When new Bahmni starts, it will “migrate” the DB (using Liquibase, it will automatically add missing columns, tables, etc).
Option2: Try this omod to create CSV exports
See this discussion: How can I export a patient's medical info from OpenMRS? - #3 by sarthak10