It's because your "Account Level 0" attribute is finding a duplicate composite of the dimension key (e.g 88 and 99 are both P&L). You need to make the KeyColumns property...

You need to use a global temporary table rather than a local one. So ##temptable instead of #temptable

You need the GENERATE function if you want to show the top ten products by customer. You have taken this out which is why your results are "garbage".

For the "0"...

Looks like a typo to me. According to the text of the book it should show the last 5 years so the calculation should be:

FILTER(MasterCalendar_T,MasterCalendar_T[Date]>=DATEADD(MasterCalendar_T[Date],-6,YEAR))

Note, negative 6.

The simplest way to do a "top 10 by customer" type thing is to use Generate to iterate over each one and perform the TopCount. The below uses this method...

Where others use variations of "foobar" for things they can't think of a name for, I use variations of "noddy". You're not the first who's...

It's because CustID is a column name. Essentially your where clause is doing 1=1.

The following will fail with an "Invalid column name" error:

DROP TABLE IF EXISTS #noddy

CREATE...

For your purposes, yes, since you are doing counts. My process is more to see what's happening and to diagnose long running queries etc.

That said, if I found a...