Here is the opinion in Thlopthlocco Tribal Town v. Stidham. An excerpt:

The Thlopthlocco Tribal Town is a federally recognized Indian tribe in Oklahoma. An election dispute arose about which individuals were properly elected or appointed to govern the Thlopthlocco people. Seeking to resolve that dispute, the Tribal Town filed suit in the tribal court of the Muscogee (Creek) Nation and, accordingly, voluntarily submitted to that court’s jurisdiction.

The Tribal Town subsequently concluded it did not want to maintain its suit in tribal court and dismissed its claims. But the defendant in that suit had, by that time, filed cross-claims. Arguing that the Tribal Town’s sovereign immunity waiver did not cover proceedings on the cross-claims, the Tribal Town attempted to escape Muscogee court jurisdiction, but, in various decisions, several judges and justices of the Muscogee courts held that they may exercise jurisdiction over the Tribal Town without its consent.

The Tribal Town then filed a federal action in the Northern District of Oklahoma against those Muscogee judicial officers, seeking to enjoin the Muscogee courts’ exercise of jurisdiction. The district court dismissed the case, finding that the federal courts lacked subject matter jurisdiction, the defendants were entitled to sovereign immunity, the Tribal Town had failed to join indispensable parties, and the Tribal Town had failed to exhaust its remedies in tribal court. We conclude, however, that the Tribal Town has presented a federal question and that the other claims do not require dismissal. But we agree the Tribal Town should exhaust its remedies in tribal court while its federal court action is abated.

Here are the briefs:

Thlopthlocco Opening Brief

Stidham Brief

Thlopthlocco Reply Brief

Lower court materials here.