Derbyshire is big. Around 1,000,000 people in 1000 square miles. Politically there are 11 parliamentary constituencies, Derby City Council, Derbyshire County Council, 8 borough and district councils and 204 town and parish councils.
Within Derbyshire, three constituencies have become strong enough “go it alone” with their own fully-constituted Green Parties: High Peak, Amber Valley. and Erewash. This makes sense where there are a lot of activists in a focused area.
For the rest of Derbyshire, Derbyshire Green Party provides central coordination. Groups within the party operate semi-independently, e.g. Derby City, Derbyshire Dales, South Derbyshire and Bolsover, Chesterfield & North East Derbyshire.