That's just a select query and not a filter. Filters are appended as AND to a WHERE statement. So your filter is being appended to the userlist query as follows.

[code:1]
(AND ( SELECT '*' FROM `ducati_comprofiler` LEFT JOIN `ducati_users` ON(`ducati_comprofiler.id`=`ducati_users.id`) LEFT JOIN `ducati_cbsubs_subscriptions` ON(`ducati_comprofiler.id`=`ducati_cbsubs_subscriptions.user_id`) WHERE SUBSTRING(`ducati_cbsubs_subscriptions.expiry_date`,1,4)='2011' ))
[/code:1]

The below query should do what you're wanting.

[code:1]
( ( SELECT SUBSTRING( `expiry_date`, 1, 4 ) FROM `#__cbsubs_subscriptions` WHERE `user_id` = [user_id] LIMIT 1 ) = '2011' )
[/code:1]

Ducatiklubben wrote:

Thanks! The syntax seems to okay, but still all members are listed. What we want to do is to list members that paied subsctiption (with CB Subs) for current year. How do we do that?

Best thing to do is to use CBSubs CB Fields integration to assign a value to a CB field when a subscription happens and remove the value when subscription ends - then just filter off this value to create your list.