Whichever operational theatre which still qualifies for an OSM. If the Afghanistan "training" role still qualifies, then Royal will be there in some capacity & I'd guess one or two matelots working in the intelligence role. During Herrick we had Engineering Technicians working with Commando Logs and lots of matelots scattered about, about 800 at one time.
I must admit this is the first I've heard of a GSM 08 although I've been away from DII for 7 months so am not up to date on DINs. There's very little on the web, with nothing apparent on the .GOV.UK website and can't find anything on the Defence Gateway.