A dating site can describe two people as local because their postcodes sit in the same county. That is only half the story. Roads, rail links, work patterns and the hills in between matter just as much.
For people in Derby, Long Eaton, Ilkeston, Belper, Ripley and the southern part of the county, regular travel towards Derby or Nottingham may already be part of the week. Someone in Chesterfield may find Dronfield or Sheffield easier than a rural address farther south. Glossop has a direct relationship with Manchester, while getting across the Peak District can be slow and weather-dependent. Buxton has its own orbit again.
The useful question is not “Are they in Derbyshire?” It is “Could we meet after work without either of us resenting the journey?”
Set your search area around the life you actually lead. If you do not drive, think in stations and dependable bus routes rather than straight-line miles. If you work shifts, a match fifteen minutes away may be far more realistic than someone seemingly close but awkward to reach. Rural members may reasonably need a broader radius, but broad does not have to mean vague.
It also helps to name the places you can reach comfortably in your profile. “Based near Matlock and happy to meet in Bakewell, Belper or Chesterfield” tells another person far more than “open to anywhere”. Clear geography saves both sides a long exchange that ends when somebody finally checks the route.