Sciliar is a very special mountain in the Dolomites with regard to many aspects.
Ascent: From Compatsch at the western border of Alpe di Siusi (1870m; up to here with Siusi cable cars; road open for traffic only in the morning and evening) follow path no. 10 in a southwestern direction across Alpe di Siusi until reaching the crossroad to path no. 5 (1900m). On this path to the left, enjoy a light downhill walk through the meadows until reaching Saltner hut (food and drinks, 1830m). Continue to the nearby bridge crossing the Frötscherbach stream, follow path no. 5 in a moderate ascent to the "Touristensteig" trail; hike up the serpentine trail to the edge of the Sciliar plateau, which you cross until reaching the Schlernhaus (2450 m); 2.5 hours from Compatsch.
Alpine trail: From Schlernhaus a short walk back on the access trail, turn right onto the almost flat or slightly ascending path no. 4 over the Sciliar plateau in an east-south-eastern direction to the western ridge of Punta Terrarossa (signpost, 2550m); now the trail soon features serpentines (one exposed area with rope, always mark no. 4) down to the southern foot of Punta Terrarossa and finally below Denti di Terrarossa cross the slopes on a good trail to Tierser-Alpl hut (2440m). From Schlernhaus 2 hours.
Descent: From Tierser-Alpl hut on path no. 2 first in a north-eastern direction and a short ascent to Forcella Denti di Terrarrossa (2499m); now in a northern direction across rock boulders in serpentines steeply down to the northern foot of Denti di Terrarossa (2250m); continue on path no. 2 in a straight hike without any major differences in altitude over Alpe di Siusi in a northern direction to Hotel Panorama (2009m) and on the access road down to Compatsch in about 20 minutes; from Tierser-Alpl hut 2 hours.