To calculate the distance of the point of descent

Can we know the ground speed on an aircraft or to deduce it from the displayed speed on Badin ?

Google is your friend…
What is knots true airspeed (ktas) | Stratos Jets Charters
and this one
How to Quickly Calculate the Top of Descent | ThinkAviation

I have already read the tutos out these subjects and have taken numerous notes. What I search is: where can I see the ground speed on the dashboard of the A 32 NX; is it on the ND in the top left corner ?

If I well understand, Sarah Fritts speaks speed above the ground, without to precise if that speed is her ground speed ? if her calculation is correct ,it is yet simpler that what I have read.

I don’t ask calculator, I simply ask how function the flypad o the 32NX, because I have not an Ipad, then I don’t know how that functions.