The ChangeMan ZMF 7.1 release notes contain a short note with a title like "Short selection list for selective promote", related to an option added to the promotion panel. However, for about a decade or so, a variation of that feature is already available in ZMF (probably from around 5.3 or so).
That feature is "hidden" in CMNEX027, with a misleading comment in it. It appears that hardly anybody knows about that hidden feature. The difference from ZMF 7.1 is that in pre-ZMF 7.1 it's an all-or-nothing setting (set in CMNEX027, typically by a ZMF admin), while in ZMF 7.1 the choice is left to the user requesting the selective promote.
To find out how to enable it in a pre-ZMF 7.1 release (like 5.3, 5.5, 5.6 or 6.1), read the Z-Redbook issue about only show promotion candidates in selective promote ... (login required).