You need to use an Index and 2 Filters with a parameter to get that. See Screenshots and attached.
Then filter this view by dragging Calculation 1 to filter and setting TRUE
Before that I created a field INDEX and put it in view. Now create a second Filter and INDEX=1 , Set it TRUE.
Change Threshold, to 20000
Next Largest.twbx 1.2 MB
hmm... I need it as a value that I can use in other calculations