I'm reading the TI-precision lab of opamp. And I'm confused with the calculation of the BW_CL (bandwidth of th close-loop).

I'm prettry sure the BW_CL= GBPW/GAIN_CL. This is very clear refer to enter link description here

What I cannot understand is why can we find/use the close-loop gain on the bode plot of "Open-loop gain vs frequency" ?

As I see I get the bandwidth when open-loop gain = 40dB !?!?