Year around it is possible to travel by bus from Zurich to Makarska, The bus from Zurich drives to Split, from there you have to change to a local bus to Makarska. Timetable below is for buses from Zurich to Split, timetable from Split to Makarska you can see here. The travel time for the 1220 km long bus route from Zurich to Makarska (via Split) is about 19-20 hours.
If you are going on Holiday and plan to return to Zurich with bus, you should buy a return ticket as this is cheaper then two single tickets