Here is a list of fields from AD which are supported per default:

 

assistant, c, cn, co, comment, company, department, description, directReports, displayName,
distinguishedName, division, employeeID, facsimileTelephoneNumber, givenName, homeDirectory,
homeDrive, homePhone, homePostalAddress, info, initials, ipPhone, l, mail, manager, middleName, mobile, pager, personalTitle, physicalDeliveryOfficeName, postalCode, postOfficeBox, sAMAccountName, sn, st, street, streetAddress, telephoneNumber, title, url, userPrincipalName, wWWHomePage

 

Extension attributes (extensionAttribute1, extensionAttribute2 etc) are also supported as well as any schema change you might have implemented. 

If you want add your own custom fields, you just need to tell Xink the LDAP name of the field and the field gets populated.