Can I see which questions a KPI is based on?

Yes! You can see which questions a KPI is based on under Results > KPI:s or Questions > Pulse library. The latter alternative is only available if you have access to the pulse. 

Under Results > KPI:s 

1. Go to the page Results > KPI:s 
2. Select a group and scroll to the KPI you want to see 
3. Click on the button "Show/hide question results that make up this KPI" 

Under Questions > Pulse library (only possible if you have access to the pulse)

1. Go to Questions > Pulse library 
2. Open the pulse which the KPI is generated from 
3. Look at the checkboxes just underneath the questions in the KPI section. The checkboxes (meaning questions) that are checked will be included in the KPI.