On the Account object I have created a formula field called Domain_Name__c . The formula I have used is this,

SUBSTITUTE(Website, LEFT(Website, FIND("www.", Website)), NULL)

Where website is a standard field on Account.

If Website is www.xyzdomain.com or https://www.xyzdomain.com

In Domain_Name__c I expected result as xyzdomain.com

Instead i am getting the result either as

.xyzdomain.com or ww.xyzdomain.com depending on whether the Email entered was 'www.xyzdomain.com' or 'https://www.xyzdomain.com'

Any thoughts how I can only get the text after the .   

e.g If, in the field Website  I enter www.salesforce.com  or  https://www.salesforce.com the result in the Domain_Name__c should be salesforce.com