Oh well, you get what you get when you don't provide DDL, sample data, and expected results. No tested code.

For better answers to your questions, please read and follow the instructions in the first article you will find referenced in my signature block below.

Now, how about this:

WITH BaseData AS (

SELECT DISTINCT

wcv.contact_name

,wcv.contact_organization_name

,wcv.workitem_title

,wcv.workitem_number

,wcv.workitem_created_on

,wcv.assigned_to_worker_name [Assigned To]

,datediff(d, workitem_created_on, getdate()) [Ticket Age]

FROM

contact_view cv

JOIN workitem_current_view wcv

ON cv.contact_email = wcv.contact_email

WHERE

wcv.workitem_status_lookup_value = 'Open' and

wcv.workitem_created_on > '2006-01-01 12:00:00.000'

)

SELECT

contact_name,

contact_organization_name,

workitem_title,

workitem_number,

workitem_created_on,

[Assigned To],

[Ticket Age]

FROM

BaseData

ORDER BY

CASE WHEN [Assigned To] = 'Group 1' THEN 0 ELSE 1 END ASC,

[Ticket Age] DESC