Have you checked out info on audiences yet?

www.msd2d.com/.../Tip_viewitem_03.aspx
egory=Deployment&id=f435eea2-0d88-4c69-a27a-7f011d447f8f

How can I design  this in WSS ?

WSS does not utilize audiences. You can look into 3rd party tools or
custom code. Or you could build out your WSS site  structure around your
"audiences" so each user  group has their own WSS site to reference.

You can do user  based roles, but you're going to end up writing a lot of customized code.

Audiences would work for this, however please note that audiences are not security groups, more just a cleaner way to display information to users using the Portal level software.

Portal will support the ability to display different information based  on Audiences Is this what you want to do?

I like to say, audiences are immature. They can be used in only two
settings and have no security purposes.

1. The Grouped Listing Web Part can be grouped by Audience. This will
only show Listings targeted to each individual. However, you must either
group by audience or by something else. If grouped by anything else, all
Listings will be shown.

2. Hide or show an entire Web Part.

Neither one of these solutions is ideal. It has its place but it is,
like I said, immature.

Unfortunately, I'm don't think that targeted content gets any better in
SharePoint 2007.