When performing an installation in text mode, a details button is missing for
metapackages (I'm not sure of the exact terminology that the comps people use -
what I mean is a package group, like 'Development Tools') that allows you to
select the individual packages to be installed.
For instance, selecting 'Development Tools' in the GUI installer makes appear a
'Details' button, which you can use to select optional packages.
The text installer offers no such facility.
Pressing F2 on a selected group should bring up the detailed selection screen.
OK, knock me on the head, I didn't see that for how many years, and it's right
there at the bottom of the screen.