java-tutorials/spring-boot-modules/spring-boot-custom-starter/parent-multi-module/pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.baeldung</groupId>
    <artifactId>parent-multi-module</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <parent>
        <groupId>com.baeldung.spring-boot-modules</groupId>
        <artifactId>spring-boot-custom-starter</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <modules>
        <module>library</module>
        <module>application</module>
    </modules>

</project>