Executions.createComponents will work with ZK Specific URI (refer to Inter-Application Communication) where "~./" in ZK Specific URI will get the file under "classpath/web/", assume your zul page under "src/web/zul/pages" as below:
And you export the src folder as a jar, then you can create component with the zul file in jar as below:
Executions.createComponents("~./zul/pages/zulInJar.zul", parent, null);