Everything we experience is a relationship. We have been conditioned to only think of interpersonal exchanges, but if you take a step back we are in relationship with everything all the time. How we interact, exchange, perceive, believe, etc. is at the core of our human experience - including what is going on inside our body, mind, and emotions.
December Breathing Technique
Honestly, this is a tough listen, but if you like naming things, having a defined system, and want someone who studies what feels like the obvious but has made it a specialty, I would recommend listening here: Dan Siegel: The Neurological Basis of Behavior, the Mind, the Brain and Human Relationships