Run an XCUI test on an already built app in macOS?

I have built a suite of XCUI tests for my macOS application. Currently when I run the tests, it first builds the application, and then runs the UI tests using the newly built .app file. We currently run a nightly build already, which is run through a series of existing XC Tests. Rather than building the app again, I would like to point my XCUI tests to the already built app (created during the nightly build), and then run the UI tests on that app.

Any ideas?