I don't think you're right, vulcan.
In the RAF a Flight is part of a Squadron, a Squadron part of a Wing, a Wing part of a Group and a Group is part of a Command.
In WW2 Fighter Command comprised six Groups (numbers 9 to 14). These were large geographical areas covering the entire country. Air Chief Marshal Sir Keith Park's No. 11 Group, for example, covered London and the South-East. These Groups were composed of a number of Wings and Squadrons (with a small number of Squadrons reporting directly to Group). It was not always a Squadron Leader in charge of a Squadron (sometimes a Wingco, very occasionally a Flight Lieutenant). Similarly some Wings had a Group Captain OIC. But essentially the structure was as I described.