NOTE: This is not currently available on the SSA3000X series.
The quality factor of a filter is defined as:
Q = Center frequency/Bandwidth
From the SSA3000X Plus, X-R, SVA1000X Series Manual:
You can find the automatic Q measurement in the Measurement function menu.
Press the Maker Fn button > Select N dB BW marker type and set the amplitude level (dB) at which you wish to measure the bandwidth (BW).
The measurements will be shown in the upper left-hand-side as shown below: