If you are using Spring Boot then you can use Pre-Liquibase module for this. It solves the chicken-and-egg problem in the sense that it allows you to execute some arbitrary SQL before Liquibase itself fires. Typically what you put in Pre-Liquibase SQL file would look something like this:
CREATE SCHEMA IF NOT EXISTS myschema;
but Pre-Liquibase even allows the SQL script to be dynamic:
CREATE SCHEMA IF NOT EXISTS ${spring.liquibase.default-schema};
More information at the website.
You can use Pre-Liquibase outside of a Spring Boot context, i.e. in pure Spring Framework. You cannot, however, use it without Spring as it relies on Spring for parsing your SQL file and executing it.