Choosing 18 holes from 27 hole course

I regularly play Orchid Country Club in Singapore. 

There are three 9 hole courses, two of which are used to make an 18 hole round of golf.  

The S60 only allows you to choose one 9 hole course at a time, rather than the two required to make 18. 

All other golf apps I have used have the course combinations e.g Aranda/Dendro, Vanda/Dendro and Aranda/Vanda. 

Why is Garmin Golf different?