Excluding dimensons that are not equal to null

[#1]

I have a dimension where some of the records are null and some contain a 4 digit code. I only want to include the null records but when I try to create a calculated dimension I just get blank records in the value fields

I've attached my QVD and its the table that is showing trading partner is where I'm looking to only include the null value records

[Gabriel]

Hi,

That's just an idea of what the Set Analysis should look like.

Try this

TEXT({<Flag_TradingPartner ={1}>} Flag_TradingPartner)

[#3]

Do I create this as a dimension ?

[Gabriel]

Yes