Evolved stars are seen as luminosity classes: IV, III, II and I, which are also called sub-giants, giants, extreme (or bright) giants and supergiants.
This is not a parallax at all, but
is a means of estimating the distance to a star from
its spectral type (OBAFGKM) and luminosity class (V,VI,III,II,I).
If we know a stars spectral type and luminosity class, then we
know in principle (see above) what their absolute Visual magnitude
should be. Comparing that to their apparent visual
magnitude tells us the stars distance!