Hi Ells and Lempster,

Thank you for your replies. What I need is the ability to find all the orders that can contain a user - specified list of products but does not contain another user - specified list of products .

There is not relation(hierarchy ) available between the products , so it cannot be grouped in this respect.

An important feature is that the user has to have the ability to pick up dinamycally both lists from the product dimension( I can create another attribute or even another dimension for the products if it gets to this). Can I apply a custom member formula or a unary operator for this?

Any other idea how to the user can generate this query dynamically in the cube (I can input MDX to get a calculated member / dimension but I would prefer without him/her having to input MDX )