Is there a way to combine keyframes in groups? Let's say, I have multiple keyframed objects.

Selecting necessary keyframes from necessary objects in lengthy Dope sheet is very tedious. 

For easier manipulation with the timeline, I want them to be grouped in "chapters" or somehow binded to Markers or whatever, is this possible?
Generally this task is demanded to Bone Layers: you can put a group of bones in a Bone Layer, then select that layer, select all bones and set keyframes.
In the dopesheet you can set the visibility to all, only selected, multiple objectes, etc with the little buttons on the header of the dopesheet window.