I have a dimensions like this.

Level1
Level2
Level3

With this particular dimension it is easy for the users to get lost so
I have set the names for the levels like this.

Level1Name = Level1Name
Level2Name = Level1Name + ' - ' + Level2Name
Level3Name = Level1Name + ' - ' + Level2Name + ' - ' + Level3Name

The problem is that I need to hide members if they are the same as
their parent on the third level. Once I emplemented this naming system
it doesn't work anymore. Is there a way to make it look at the
underlying data, which is the same as the parent, rather than my custom
name? Or is there some other way of doing this? I can imagine adding
a new column to my relational database to solve this problem but I
really don't want to do that.

I tried to add something like this to the Member Name Column but AS
wasn't happy.

IIF(Level1Name + ' - ' + Level3Name = Level2Name, Level2Name,
Level1Name + ' - ' + Level2Name + ' - ' + Level3Name)