This is a "how the f*** does that come apart" question :)
Its like this one, except mine is goldplated
Problem is that something is stuck so I can only get bath water out of it, no flow from the shower side.
This guy had the same problem and his photos are good although he didn't get an answer
I had difficulty removing the valve actuator, but after seeing his 9th pic realised my spindle was stiff and I needed to grip it with pliers to stop it turning as I turned the actuator assembly with a spanner. Previously the spindle and was turning as well, causing the pin to jam in the valve inards. Once I held the spindle still, the actuator unscrewed easily.
Now I can see the valve as in pic 11 (the last pic), but to access it I think either or both the top or bottom connections muust be removed. Unlike that diynot tap, mine does not have a nut holding the shower connection to the tap as per diynot pic 2, but is like this
Phil