TCR is the market place solution Reporting Compliance.
I think, we need some additional information.
If you only want to restrict the drop down list by user, than you can do it, depending how you set the drop down list up.
- If you maintained the drop down list manually using one of the Control Lists, then you have to change to a parameter based solution.
- If the drop down list is based on a parameter (Member List, Member Dialog), the security of the cost center dimension should control the drop down as well.
- If the drop down is a bound list using a Business Rule, you can change the rule to filter the cost center by user.
If the drop down list is not based on a Business Rule, you always can change it to do so.
Within a business rule, you find the active user in the si object: si.UserName
I hope this helps for the moment and cheers