idans,
The only way to "see" an attribute of a reference attribute in in the BO that contains is is by declaring a Shortcut to the referenced attribute.
TIP: To use attributes of the referred instances in conditions define shortcut attributes that refer to the required attributes (see Reference Attributes and Setting Properties of Shortcut Attributes) and use shortcuts instead of reference attributes.
Also
NOTE: A shortcut path may only be via a single reference – multiple references are not acceptable as it is not clear the attribute value of which particular instance of the referred object should be displayed.
Please see pages 146 and 201 of the User Guide.