It depends.
AFAIK commute/position into the UK as a passenger, not as part of the operating crew, and you’ll be required to self-isolate (“quarantine”), even if you are traveling in prior to duty.
The exemption is so that the crewmember can leave quarantine to travel directly to/from a place of duty such as training, or to operate at any time during their isolation period.
FWIW I suspect the wording is as it is (“place you are staying”, rather than “in your hotel”) because it allows those non UK resident crew arriving from an Amber list country who have the option of self isolating somewhere other than a hotel can do so.