The reason is here, Without indicating anything it wont work. Because as per Mathematics agenda or algorithm it won't understand to club 2 values in single value. That is how the Parenthesis works in Qlikview and it can split into two values and the separated work as Single value by mid of Hyphen. And Parenthesis can consider as one Value and Second value then we are clubbing into one by using Hyphen.
Before develop something, think If placed (The Right information | To the right people | At the Right time | In the Right place | With the Right context)