וּבָאתָ֗ אֶל־הַכֹּהֲנִים֙ הַלְוִיִּ֔ם וְאֶ֨ל־הַשֹּׁפֵ֔ט אֲשֶׁ֥ר יִהְיֶ֖ה בַּיָּמִ֣ים הָהֵ֑ם וְדָרַשְׁתָּ֙ וְהִגִּ֣ידוּ לְךָ֔ אֵ֖ת דְּבַ֥ר הַמִּשְׁפָּֽט׃
and appear before the levitical priests, or the magistrate in charge at the time, and present your problem. When they have announced to you the verdict in the case,
Torah Temimah points to Sanhedrin / Sifrei.
אל הכהנים וגו'. כהנים לוים ושופט — מלמד שבית דין מורכב מכהנים ולוים וישראל.
English: To the priests… and to the judge — this teaches that the court is composed of priests, Levites, and Israelites.
The listing of both the levitical priests and the judge establishes the mixed composition of the high court.
Derash on the verse (Bavli / Sifrei) — not a formal named middah of the 13. The dual address is read as requiring both priestly and lay judges.
The Great Court includes both kohanim/leviim and ordinary Israelite judges.