Hi,
If you don't want to process the subreport all the time, I suggest to add a link to the main report, then use that link to navigate to the sub report. And if you want to back to the main report, we could use the BackButton of the ReportViewer to achieve.
I look forward to receiving your test results.
Sincerely,
Zong-Qing Li
Microsoft Online Community Support
Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as
Answer” if a marked post does not actually answer your question.