Chesterfield is served by the 465 and two 560 services daily.I remember the London to Lincolnshire corridor seeing some reductions towards the end of 2019 with some stops removed from the network. Maybe that explains why Peterborough has never returned- usage of the routes was in decline.
Not strictly withdrawals but there are no longer any NX services from South West to Birmingham via Gloucester. Between Bristol and Birmingham they now stop at Cheltenham only. In addition Derby only recently seemed to return to the Birmingham to Bradford corridor with one journey each way and I'm not sure if Chesterfield has ever come back.
My memory was that Birmingham-Derby-Birmingham was quite popular so I'm quite surprised this got removed for so long.
I fair few services do Birmingham - Leicester - Nottingham before heading North.