Making Groups in Ableton Live is really easy.

Ableton Live - Group Channel

One of the best things about Ableton Live is its flexible routing structure. People coming from other DAWs or beginners overlook how easy it is to make Groups in Live. I like to have each of my drum sounds (snare, hi hat, toms) on separate channels each with their own relative volume, panning and effects. I then put them into a Group channel to control the overall volume of the drums with just one fader. The Live User Manual calls Groups “submixes”:

Suppose we have the individual drums of a drum kit coming in on separate tracks for multitrack recording. In the mix, we can easily change the volumes of the individual drums, but adjusting the volume of the entire drum kit against the rest of the music is less convenient. Therefore, we add a new audio track to submix the individual drums. The drum tracks are all set to output to the submix track, which outputs to the Master. The submix track gives us a handy volume control for the entire drum kit. – Ableton Live 7.0 User Manual

Take a look at the screenshot above (click it to see it in a larger size). Create your drum channels or any audio or midi channels you want to have Grouped together. Next create an audio channel (Command-T). Name your new audio channel “Group” (Command-R to rename). On each of the channels you want to be part of the Group find the Output Chooser drop down menu and select “Group”. The Output Chooser menu is directly below the label that reads “Audio To”. The last thing you need to do is set the Monitor to “In” on the Group channel. This way you can hear your new drum Group!

Do you use Groups?