How to group selected animation keyframes in the «Graph Editor»

Question

There is a similar method in Edit Mode: Vertex Group. I need something similar but with animation keys in the Graph Editor.

Description of video: A demonstration of selecting vertices in a mesh and then adding them to a vertex group. This is followed by selecting keyframes in an F-Curve and a question mark — meant to indicate the desire for the equivalent functionality, a sort of "vertex group" for keyframes.

Advantage / application animation key grouping:

1. Analog - NLA but in one action. Replacement / alternative to NLA. Place the grouped cycles of different gaits in one action further along the timing, in order to substitute one or another grouped part of the desired cycle in the right place of timing in the process.

Answer 1

The keyframes in an F-curve are equivalent to the handles of a curve object and there is no available method for collecting a subset of the handles to create the equivalent of a vertex group.

But you hit on the way Blender solves what appears to be your underlying request. This is precisely what the Action Editor is meant to provide. Actions are the equivalent of the subsets, but instead of simply having collections, you create the F-curve in a two step process, by combining actions in the NLA.