There are many reasons this could be happening! Seeing your post title, waiting for the page to load, my head flickered to a dataset of 25M rows X 90+ columns I was working with, and the tuning I had to go through.
The surefire way to triage this -
1. Start with your map, with both variables removed from the viz
2. Go to Help>Settings and performance>Start performance recording
3. Drag both of your measure to where you originally placed them to cause this performance issue
4. Help>Settings and performance>Stop performance recording
5. Tableau will generate a workbook (it will open automatically, give it a second)
6. Post the workbook it generates! (it only has information related to the queries it received, no proprietary data!)
Thanks for your response. Here is the attached workbook. I also attached the screenshot my work sheet. I am working with two variables (x01 and x02) and calculating new variable dd. when I drag the new variable to the map, It works fine. But when I changed the date filter and the parameter (threshold), it took long time. Please let me know is there any solution without reducing the data.
Can you click on the query that took 64 seconds and give me some more information? If you dig into it, it should give you more information.