Ableton Live needs to see OSCulator as a MIDI input device. This usually happens automagically, but it never hurts to check. In Live's Preferences dialog, check if OSCulator Out is available and Track and Remote are checked under the MIDI/Sync tab. If all is well, you can now MIDI learn a control in Ableton Live.
Ableton Live Control Surface Mode. Thanks to Julien Bayle who decompiled the Python MIDI Remote Scripts in Ableton Live, I wrote one for the MIDI Touchbar. You can now control most channel and device parameters in Live. MIDI Touchbar will give you access to the parameters of the selected channel or device (instument and effect).