java: duplicate class - build order

Here is the translation into English:

Our company's core Java files are located in the main/java package, and these core files cannot be modified individually by each client. Therefore, to manage the parts that need to be changed for each client, we create separate folders like main/client/b and write new parts there, managing the changes from the core files. We use the same package name and the same name for the Java files.

When we used Eclipse, we could specify the build order, but I'm wondering if IntelliJ IDEA lacks this feature?