Liferay Groovy Script to get all site ids nested within a site when passing this site id as parameter

siteGroupIds.groovy

import com.liferay.portal.util.*;
import com.liferay.portal.model.*;
import com.liferay.portal.service.*;
import com.liferay.portlet.journal.*;

try {

    company = PortalUtil.getCompany(actionRequest)
    companyId = company.getCompanyId()

    global = GroupLocalServiceUtil.getGroup(companyId, companyId.toString());
    globalGroupId = global.getGroupId();

    parentGroup = GroupLocalServiceUtil.getFriendlyURLGroup(companyId, "/site-friendly-url");
    siteGroupIds = getSiteGroupIds(parentGroup.getGroupId());
    out.println(siteGroupIds);
} catch(e) {
    out.println("""<div class="portlet-msg-error">${e}</div>""")
    e.printStackTrace(out)
}

def getSiteGroupIds(parentGroupId) { 
    def siteGroupIds = [];
    siteGroupIds << parentGroupId;
    list = [];
    q = list as Queue;
    q << avisonYoungGroupId;

    while(q.size > 0) {
      currentGroupId = q.get(0);
      currentGroup = GroupLocalServiceUtil.getGroup(currentGroupId);
      childrenGroups = currentGroup.getChildren(true);
      out.println(childrenGroups);
      for (Group childrenGroup : childrenGroups) {
        childrenGroupId = childrenGroup.getGroupId();
        q << childrenGroupId;
        siteGroupIds << childrenGroupId;
      }
      q.poll();
    }
    return siteGroupIds;
}