Does "הדבר הקטן" refer to monetary matters (דיני ממונות) and "הדבר הגדול" refer to criminal matters (דיני נפשות) or were they also allowed to judge נפשות? (Shmot 18, 21):
"...וְשַׂמְתָּ עֲלֵהֶם שָׂרֵי אֲלָפִים שָׂרֵי מֵאוֹת שָׂרֵי חֲמִשִּׁים וְשָׂרֵי עֲשָׂרֹת׃ וְשָׁפְטוּ אֶת־הָעָם בְּכָל־עֵת וְהָיָה כָּל־הַדָּבָר הַגָּדֹל יָבִיאוּ אֵלֶיךָ וְכָל־הַדָּבָר הַקָּטֹן יִשְׁפְּטוּ־הֵם ..."
"Set these over them as chiefs of thousands, hundreds, fifties, and tens, and let them judge the people at all times.Have them bring every major dispute to you, but let them decide every minor dispute themselves."
This is a follow-up question on "Yitrohs-advise-to-moses-on-appointing-judges