Sometimes the calculated fields don't show up in the list and no doubt someone out there knows the logic behind it, perhaps something to do with table calculations in your calculated field, but that's speculation rather than fact.
There will be alternative ways to do what you want. You could try creating an INDEX() and filtering on that. You could drag the measure to be the first pill in the Rows shelf, make it discrete and untick Show Header. There are options, all depends on the specifics of what you hope to achieve.
Thank you Andrew!
I'm open to suggestions of how else to do this - I want to get the Top 20 Titles based on Indexed Streams. So, the 20 highest Indexed Streams values.
How do I create an INDEX()? Any other suggestions?
As you're partitioning by Date it adds a level of complexity. Can you share the formula behind Indexed Streams?
It'll be worth exploring the RANK function as well: Rank Calculation. You should be able to filter for the top 10 by rank if you can get the ranking to work appropriately.
You may also be able to create a window_sum table calculation on the Indexed Streams to show the total ignoring the Month partition.
The Indexed Streams are just "SPS"*1000. SPS is a more complicated formula.
The RANK function replaces the Indexed Streams value with a rank number. So, that doesn't seem to work.
I could potentially just use June and get rid of May; would it make it easier to have one date column?
If you just have 1 date column then it's easier. However it should still be possible with the Rank. The Rank should return the order (the rank) of the Indexed Streams, which would be a number with hopefully the largest being 1, the next largest number 2, etc