Near you, NCN6 Castlethorpe-Milton Keynes enabled Castlethorpe residents to access the Redway network, but I think it's not a great standard (only macadam, one step up from gravel).
Deanshanger-Stratford should have enabled similar access to the Redways from Deanshanger, and they built alongside the A422 Deanshanger to Old Stratford to a pretty good standard (except for some very non-MK 1990s crap barriers), linking the two 30mph zones, and then the final step into Stony Stratford collapsed in a squabble between the two councils over who paid what and I don't think South Northants (now West Northants) have attempted to build another village link since, so maybe not an example you want to cite if you're wanting LB to MK upgraded! It might be OK if you're looking for a cycleway alongside the A505 as a more direct link to the Sewell Greenway into Dunstable/Luton, or to get the LB-Wing link improved+completed.
I had a bit more of a look around, but local examples seem thin on the ground. Bedford is a farking disaster zone, yet again. There, several nearby villages are almost linked but cyclists get abandoned to cross the A421 or A6 or A600 or some other big road. And Bedford doesn't have a decent cycle network anyway, with mainly the NCN51 Varsity Way and some spurs.
Further afield, the completion of NCN33 to/around Long Ashton connected the town of Nailsea to Bristol's cycle network.
The extension of NCN 334 from Abbot's Leigh to Pill does similar for linking that village to Bristol and improves the link to Portishead, but as far as I know, it hasn't yet been given the route number because it contains some substandard bloopers (needless narrow bits and restricted side road crossings, and so on) that I think Sustrans are holding out for fixes for.
NCN244 The Two Tunnels connected Midford to Bath but that might be more expensive than Central Bedfordshire need to know!