I have a question with a custom column that is the sum(x)/sum(y) where x and y are columns in the original question.
This is grouped by Date.
Problem is that I need to filter by values in the query from before the summary. That is by using a column that's not in the resultset.
If I add the column(s) to the summarize by (group by), the percentages are then summed for the chart so are meaningless.
Is there a workaround or do I just need to display the data without using a custom column?
Hi @AndrewMBaines
You're seeing these issues - upvote by clicking 
on the first post of each issue:
https://github.com/metabase/metabase/issues/19744
https://github.com/metabase/metabase/issues/17775
Yes, definitely the first one, not sure I understand the 2nd.
It's frustrating as the calculation can't be done in a view.
@AndrewMBaines You can do the calculations in a database View, or using SQL.
The problem is how the inferred metadata is parsed down from nested queries. We're working on it.
Sadly, in this case, I can't do the calculation in the view or SQL. It's a % of two sums by a group by. My filter limit is due to not being able to add columns to the group by without breaking the % calculation.