Here is the opinion in Window Rock School District v. Nez.

An excerpt from the court’s syllabus:

The panel held that it was “colorable or plausible” that the tribal adjudicative forum, the Navajo Nation Labor Commission, had jurisdiction because the claims arose from conduct on tribal land over which the Navajo Nation had the right to exclude nonmembers, and the claims implicated no state criminal law enforcement interests. Well-established exhaustion principles therefore required that the tribal forum have the first opportunity to evaluate its own jurisdiction, including the nature of the state and tribal interests involved.

Briefs and lower court materials here.