For the first requirement, change your filter pane's expression to this
=Aggr(if(Count([DateOf Chg])>1,'y','n'), [Link-SO&Item])
Not sure how to get the 2nd req working
Test.qvf 288.0 K
Sorry for the late reply.
Your expression works, thank you so much
For question 2, seems the selection can't display on top bar if we set expression in master item (dimension)
Lets say if I set 'Today()-Order Date' in master item (dimension), the result is same that nothing shows up in top bar after I select data in this new dimension