Hi - Can values from a value set be combined using a dependent value set in SIT?

I have an independent value set holding the (example) values 1,2,3,4 & 5

In a Special Information KF I wish to create the following:

Segment 1 - to hold one of the above values

Segment 2 - to hold one of the above values

Segment 3 - to hold the values from Segments 1 & 2 combined

eg

If Segment 1  = 3

and Segment 2 = 5

then Segment 3 should display 3/5 automatically

Can anyone confirm if this is possible and if so, how the value set should be configured to achieve this?

Many thanks

Andy