I'm having trouble finding it on nlrb.gov's site or Google w/ `site:www.nrlb.gov`.
It looks like it may be this [0][1]. But, that case doesn't mention Damore as a participant, though it does list his lawyer: Dhillon Law Group, Inc.
[0] NRLB Case: https://www.nlrb.gov/case/32-CA-205351
[1] Advice Memo (PDF): http://apps.nlrb.gov/link/document.aspx/09031d45826e6391