The workout graph will show the planned workout intervals. The intervals are colour-coded to match the corresponding 4DP effort. Blue = efforts up to and including FTP, yellow = MAP, orange = AC, and magenta = NM. Expect that the intervals will be reaching power targets within these values of your 4DP profile.
A- The threshold line, seen in the image above is set to your current FTP. Changing your workout intensity will change the threshold line and the targets accordingly.
B- The workout progress bar will move when the workout player is in Play mode. To fast-forward or rewind a workout, PAUSE the workout and then drag the workout progress bar to where you would like to resume the workout.