How to multiply while consolidating the values...instead of adding

Dear experts,

Can you please tell me that how can I frame my dimension members , so that when they gets consolidate automaically, then they should be multiplies instead of being summed-up.

I have a situation where in I have a hierarchy. In that hierarchy, one of the node is calculated by the multiplication of its base members. And rest of the hierarchy has same summation of child nodes.

So can you suggest the proper way to do that.

Thanks

Sanjay