Tiling across different surfaces

[CarbonSM]

Hello,

Looking to do a bit of tiling but am a bit stuck where to start.

The area we are looking to tiling is part floorboard, stone and brick and I am not sure on the best option for it.

My ideas:
- Backerboard on the floorboard and then tile adhesive to level across all 3 surfaces
- Self leveling compound across all 3 surfaces and then tiling on top
- Use decoupling material across all 3 surfaces and then tile on top

What would be the best or am I missing the mark completely?

I've uploaded an image of the surfaces I want to cover, obviously need a bit of cleaning beforehand!

Thanks

 

[foxhole]

Backer board or ply, can’t see any bricks in the floor surface?

 

[CarbonSM]

Thanks @foxhole how would you attach the board to the stone on the right? Bricks are in the fireplace area, intending to tile that section too as it will not be a functional fireplace.

 

[foxhole]

Screwed and glued.