Sumif when the criteria changes. I know you can't do Sumif but all the alternatives I have found have a fixed criteria where you type it in. In my case, each row the criteria changes.

The FIXED part of the calculation above

{ FIXED [Name Id] : SUM(
    IF [Parent ID] = [Name Id] THEN [Name Sales] ELSE 0
) }

would say: for each [Name ID], get me all of the rows with that [Name ID]. Let's use 1000 as an example. So, in the context of all of the rows that have a [Name ID] of 1000, check whether the [Parent ID] is the same as the [Name ID]. There is only one row for each [Name ID], and the [Parent ID] is (fairly logically) never the same, so for our example, 1000 is not equal to 2008, that is the only comparison that is made for [Name ID] 1000. That is why the values all come out as zero. The calculation is not "scanning" the [Parent ID] column for matches with each row of the [Name ID] column, an LoD calculation works specifically within the level of detail you specify, you can't then step outside that level of detail to compare with other records.