Sum In Where - Formula

Hi,

I am struggling to write a formula.

I need to add the [PL Daily] together for each [Trader Name Primary] for each [COB as Date] where [Trader Alias] is not null.

So this is the original data:

And this is what I am trying to achieve:

The formula I have written so far is this:

SUM=Sum([PL Daily] In([Trader Name Primary];[MUSBI - PnL Exception].[COB as Date]))

But I am struggling to add the where clause. Remember, I only want to sum the [PL daily] for each [Trader Name Primary] for each [COB as Date] where the value in the [Trader Alias] is not null.

Thank You