I've not been down here for ages, so I don't know the current layout. But I do recall it being simpler in the past.

Check: are the surrounding cycleways and footways really physically separated from one another by anything significant? Apart from this little triangle where they all meet, of course.

If it's just a bit of paint or a drop kerb or something you can easily bile across → map it as one way

If it's a big kerb that prevents scooters/bikes/wheelchairs from moving between paths easily (or a fence) → map them as separate ways

https://wiki.openstreetmap.org/wiki/Tag:highway%3Dcycleway

See also the "Note that this variant is controversial as there is no physical separation between the two ways. Use another variant if possible" on https://wiki.openstreetmap.org/wiki/Bicycle