0.16 removed UI access to the "Use item groups" and "Use item subgroups" interface options. This re-implements those options via per-player mod settings and API calls. Note that they are also still in config.ini, so for plain-vanilla use if you never change settings during play you can just edit that without the mod.

This is for people who use ^F to shrink the available selection, e.g. ^Frret when setting up an assembler will always put turrets in a predictable place, for pure-muscle-memory selection when item groups are toggled off. Some things don't really have convenient left-hand-only searches or tend to work exclusively within a single group, so toggling the groups back on when e.g. setting up combinator computing on a lot of derived signals works well there.