here's what I do currently in the netbeans part of the mavenide project to
 find the relevant subprojects/sibling projects. I check if the user has
 defined the maven.multiproject.includes property in any of his properties
 files for the current project. if yes. then I'm able to find projects that
 can be offered to be opened together with the current project.
 problems with the current solution are:

import javax.inject.Inject


@CacheableTask
abstract class IncubatingApiReportTask : DefaultTask() {

    private val additionalClasspath = project.objects.fileCollection().apply {
        from(
            project.configurations.detachedConfiguration(
                project.dependencies.create(project.the<ExternalModulesExtension>().futureKotlin("compiler-embeddable"))
            )
        )
    }

    @get:InputFile

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.project;

import java.util.List;

import org.eclipse.aether.graph.Dependency;
import org.eclipse.aether.graph.DependencyNode;

/**
 * The result of a project dependency resolution.
 *
 * @deprecated use {@code org.apache.maven.api.services.ProjectBuilder} instead
 */
@Deprecated(since = "4.0.0")

        File pom1 = new File(pom0Basedir, "p1/pom.xml");

        // load everything...
        MavenProject project1 = getProjectWithDependencies(pom1);

        assertEquals(pom0Basedir, project1.getParent().getBasedir());
        System.out.println("Project " + project1.getId() + " " + project1);
        Set set = project1.getArtifacts();
        assertNotNull(set, "No artifacts");
        assertFalse(set.isEmpty(), "No Artifacts");

            SourceRoot newSourceRoot = new DefaultSourceRoot(project.getBaseDirectory(), scope, this.getDelegate());
            sourcesList.set(index, newSourceRoot);

            // Update the project's sources, preserving order
            project.sources.clear();
            project.sources.addAll(sourcesList);
        }
    }

import org.apache.maven.plugin.version.PluginVersionNotFoundException;
import org.apache.maven.plugin.version.PluginVersionResolutionException;
import org.apache.maven.project.MavenProject;
import org.apache.maven.project.artifact.InvalidDependencyVersionException;
import org.apache.maven.settings.Settings;
import org.codehaus.plexus.component.repository.exception.ComponentLookupException;

/**
 */
@Deprecated

        // TODO: Eventually, all projects should explicitly declare their target platform(s)
        usedInWorkers = false
        usedInClient = false
        usedInDaemon = true
    }

    // TODO: Most of these properties are the same across projects. We should
    // compute these at the settings-level instead of the project-level.
    identity {
        baseName = "gradle-$name"

                }
            }
        }
    }

    @JvmName("associateGroovy")
    fun Project.associate(groovyCompile: TaskProvider<GroovyCompile>) {
        if(!(OperatingSystem.current().isWindows && System.getProperty("os.arch") == "aarch64")) {
            groovyCompile.configure {
                val javaToolchains = project.the<JavaToolchainService>()

<project>
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.apache.maven.test</groupId>
  <artifactId>project-with-build-extensions-plugin</artifactId>
  <version>1.0</version>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>
        <artifactId>maven-it-plugin</artifactId>
        <version>0.1</version>
        <extensions>true</extensions>
        <executions>
          <execution>

        // load the child project, which inherits from p0...
        MavenProject project0 = getProjectWithDependencies(pom0);
        MavenProject project1 = getProjectWithDependencies(pom1);

        assertEquals(pom0Basedir, project1.getParent().getBasedir());
        System.out.println("Project " + project1.getId() + " " + project1);
        Map map = project1.getArtifactMap();
        assertNotNull(map, "No artifacts");