Banjo Dm7 chord (Open G)D minor seventh on the 5-string banjo: 0 2 1 3, and 5 more shapes

Frets, string 4 to string 1: 0 2 1 3 (open position)

1. String 4 (D): open, D
2. String 3 (G): 2nd fret, middle finger, A
3. String 2 (B): 1st fret, index finger, C
4. String 1 (D): 3rd fret, ring finger, F
5. String 5, the short g: open, G, not in the chord

Sounds: D A C F  ·  Dm7 is D, F, A, C (1 · ♭3 · 5 · ♭7)

The 5th string: the short g adds the 4th over Dm7, a colour rather than a clash.

Open G tuning: gDGBD, the short 5th string first, then strings 4 to 1.