Create double validation with DimensionOverride

Hi..

I need resolver a problem with a filter and seleccion with two dimension, I have a Account Dimension  and Cost_Center dimension , I have a propierty class in the Cost_Center dimension  that mark each center how "O", "A", and "W", in the Account  dimension, one Account can pertenecer a center different and can be "O", or "A", or "W", for this I create one propierty and assigned each class, when I select in the report some center I need identify wich account are type "O" for example, but how have the center in diferent propierty, I don´t know how i do, I try with dimension override and include a validation with "OR" but It does not work, because not recognize the "," nor "+" to the validation.

Please someone can help me with other idea?

Thanks