Google Tag Manager | Rewrite referrer for subdomain

// Replace referrer to identify traffic from specific subdomains
// https://www.bounteous.com/insights/2014/06/19/are-you-missing-referral-traffic-universal-analytics/


function() {
    var theReferrer = document.referrer;
    if (theReferrer) {
        var myProtocol = theReferrer.match(/(https?:\/\/)/);
        var myDomain = theReferrer.match(/\/\/tatooine\.com(.+)/);
        var mySubdomain = theReferrer.match(/\/\/(.+)\.tatooine\.com(.+)/);
        var myPath = "";
        if (mySubdomain) {
            if (mySubdomain[2]) myPath = mySubdomain[2];
        // exclude referrals from the jobs subdomain
        // see referrals from all other subdomains
            if (mySubdomain[1]=="jobs") {
                return myProtocol[1]+"jobs.tatooine.com"+myPath;
            } else {
                return myProtocol[1]+mySubdomain[1]+".tatooinetheplanet.com"+myPath;
            }
        }
        // keep the else-if statement to see referrals from the main domain
        // remove it to exclude referrals from the main domain
        else if (myDomain) {
            if (myDomain[1]) myPath = myDomain[1];
            return myProtocol[1]+"tatooinetheplanet.com"+myPath;
        }
    }
    return document.referrer;
}