Where in limits.conf can you limit the number of results exported from Splunk's UI?
Version 6.x.x and up
It's in the limits.conf documentation. If you're only able to export 10000... just search the documentation for 10000.
The answer is different depending upon your search. These are common limits that cause issues and their defaults:
max_count = 10000
maxresultrows = 50000
But you'll see many different limits for many different commands. Then you'll have to compare to the commands you use in your dashboard/report/whatever youre exporting.