BEx Variable defined on Navigation Attribute does not appear in Parent InfoObject variable list

Hello Experts,

In BEx Query Designer 7.x, is it possible to be able to use a BEx Variable that is defined on a Navigational Attribute, within the Parent InfoObject restriction? If yes then how?

Please see example below. We are able to see the Variables that are defined within the parent InfoObject (e.g. ZVAR in ZPLANT) in the list of variables available within it's respective Navigational Attribute element usage (e.g. ZVAR is available in list of ZREGION__ZPLANT), but not the other way round.

Hope the question is clear. Any help will be greatly appreciated. Thanks in advance.

Regards

Nirmit