Here’s a simple way to loop audio and/or midi clips in Ableton’s session view:

Just add these devices (available together or separately) , to audio or MIDI tracks in Ableton. Once you do, each clip slot becomes a looper.

Choose how many bars you want to loop, start recording audio or midi  in a clip slot, and the device will automatically stop the clip slot recording after the chosen number of bars.

You can also key map the device to be able to change loop lengths on the fly: