How to use complicated nested case statements?

I have a SQL statement to calculate some stats data for analytical report purpose, it's working good:

select
SUM(CASE WHEN (createDate = CURRENT_DATE AND exitDate IS NULL) THEN 1 ELSE 0 END)
...
from sample table
group by ...

Now I want to add more complicated logic to the script (adding nested "AND" and "OR" logic), something like:

select
SUM(CASE WHEN (createDate = CURRENT_DATE) AND (exitDate IS NULL OR (exitDate > CURRENT_DATE)) THEN 1 ELSE 0 END) AS survey_Tasks_Started_And_Not_Completed,
...
from sample table
group by...

The purpose is, when createDate = CURRENT_DATE, I want to include records of both (exitDate field is null) or (exitDate is later than today)

But seems it's not working if I add too many parenthesis and nested statements... Any solution for this kind of issue when adding complicated nested case statements in MySQL?

Or is there any recommendation for better solution for such common scenarios since too many nested level cause issue too?

Thanks!