Unless you get written permissions from the local Aviation Authorities, you need to take your CPL training and test in the same country as you take your ground exams.
Except when the two countries are the UK and ROI, who have a bilateral agreement to allow the theoretical knowledge to be completed in one state and the flight training in the other. The State of Licence Issue in this case will be the one in which the flight training is completed, which will, in turn, dictate in which state you must obtain the Class 1 medical.
It is highly unlikely that the Swiss FOCA would issue a licence based on TK completed elsewhere, except in the most exceptional circumstances, and neither the UK nor the ROI will issue a licence based on flight training completed in Switzerland.