Nemoaz,
The Territorial Army SAS Regiments (21 and 23) undergo the same selection as 22SAS, but due to the part-time nature of the Territorials, the selection process is stretched over a period of one year. They get a tiny bit of slack on the long drag about 30 mins, this is a 40 mile hike over the Brecon Beacons, with a 55lb bergen plus food etc, to be completed in 20 hrs if your 22SAS, a lot of very tough good soldiers I know, didn't make it. But they (21 & 23 SAS) have to complete all other aspects of selection.
If they decide to go to 22 SAS, they have to do re-selection in 22 SAS's aloted time scale