I believe there is 15 premises in my village that would need connected, so we would just need to buy a single fibre from the fibre cabinet which is 5km away and bring that to the center of the village to a splitter node and then each person would need to pay for a fibre cable to there premises? Is that how it would work?
Kind of. The money spent won't really be in terms of "one fibre from x to y". It is more about getting a single cable, with multiple fibres, from x to y. Some fibres for service, some for expansion, and some spare for breakages.
BT have been playing with their design of FTTP-on-Demand, trying to make it cheaper to deploy. With that design, the plan for your village would likely depend on how many poles (or chambers) are needed to supply the 15 premises.
I could see them coming up with a design where they put an 8-way splitter back at the aggregation node, and using 4 fibres from that splitter for service to your village. The 4 fibres might be carried in a cable of 12 fibres, or of 24 fibres (they seem to come in multiples of 12). Or perhaps in 4 separate cables in the duct.
On arrival in your village, they could install 4 separate 4-way splitters on different poles - each pole then providing service to 4 properties.
Then each person would pay for the connection from the pole to the home.
On the other hand, they might decide that there is scope for the fibre to your village to be an extension to the spine, with a future plan to go beyond your village to the next one. That could change plans around.