2 depts selection of Value prompt Report shows The "set" node is not expected t

[tarunkrdas2013]

I have DMR report where when i select 2 depts like atached in screenshot ..My expression for selection of department  is

set([Hierarchical].[Company].[Location] -> ?p_Department?)

Report gives output  fine when i select only Location (All) or i select only United States or i select only Canada,but when i select the way i attached in screenshot error comes as

The "set" node is not expected to be a "set".

[Francis aka khayman]

i am interested to see the correct solution as well. in the meantime how about if you do not use a set?

[Hierarchical].[Company].[Location] -> ?p_Department?

will the situation reverse?  i.e. selection in the screenshot ok; Location(All) returns an error

[tarunkrdas2013]

i changed the expression of Departments to [Hierarchical].[Company].[Location] -> ?p_Department? again got same error when i selected the department as mentioned above .
On other hand when i select Location(All) report shows output correctly

[tarunkrdas2013]

hey just to update any other person looking for  a solution to this ,i wrote  below expression and it worked

descendants(set([Hierarchical].[Company].[Location]-> ?p_Location?),0)