Bolzano Airport: Best only if the flight schedule happens to work: get into Bolzano rail/bus station (short local bus or taxi), then take Südtirol Mobil bus 350 up Val Gardena to Selva. Allow about 2 hours airport-to-village and roughly €12–25 total. A private airport transfer is faster, but expensive enough to make it poor value for one or two people.
Ponte Gardena/Waidbruck railway station: This is Selva’s useful rail gateway, not a station in Selva itself. From the station take Südtirol Mobil bus 350 through Ortisei and Santa Cristina to Selva; allow about 40–50 minutes and roughly €5–10. It is the sensible arrival point when coming by train from Bolzano, Verona, Brenner or Innsbruck.
Innsbruck Airport: Take bus F to Innsbruck Hauptbahnhof (about 20 minutes), then rail south via Brenner/Brennero to Ponte Gardena/Waidbruck and bus 350 to Selva. Count on 2½–3½ hours with connections and about €25–45. A rental car or pre-booked transfer is quicker, around 1¾–2 hours, but do not assume a walk-up airport taxi will be economical.
Verona Airport: Take the Aerobus to Verona Porta Nuova, train north to Bolzano or Ponte Gardena/Waidbruck, then bus 350 to Selva. It is a realistic 3½–4½-hour journey, usually around €25–45 depending on the train. This is better than paying for a long private transfer unless you are splitting it among several people.
Munich Airport: Use the S-Bahn to München Hbf, then long-distance/regional rail via Innsbruck and Brenner to Ponte Gardena/Waidbruck, followed by bus 350. Budget 4½–6 hours door to door and roughly €45–90 if booked sensibly. Munich has far more flights than Bolzano, but it is not a quick Dolomites airport.