Cascading Filters in Bex Query ?

Hi,

I have a requirement for a basic bex query (which then feeds into a Webintelligence report) and was hoping someone could help.

At the moment I have a number of filters which restrict the query, period, country etc, users are prompted for these values at runtime

I would like to add another filter - cost center, but I assume that if I simply filter on cost center, it would display all cost centers for all entities.  What I would like for example, if I chose USA as the country filter, then only those cost centers for USA to be displayed and be able to be filtered upon.

In BusinessObejcts/Webintelligence we can achieve this when the query is from a 'traditional' universe (cascading prompts), not from a bex/bics query.

Can the same be done in the bex query instead?

Thanks