Here's a picture of how to create a typical ADSR envelope in Dimension Pro:
Attack: In a standard ADSR envelope, there's no 'Attack Level' but 'Attack Time'. Therefore, the second node must remain at maximum level. Dragging it left/right you adjust the attack time, the value is displayed in the readout.
Decay/Sustain: The third node defines simultaneously the Decay Time (by moving it left/right) and the Sustain Level (moving it up/down). The place where the orange line falls is the level the EG will keep until you release the key, once it's reached.
Release: The fourth node needs to go down to minimum, as the Release in a standard ADSR controls the Release Time (not Release Level). Moving the node left/right will determinate the type of Release. I have used Natural Release (blue line) here, due most ADSR have exponential release.
-René