Moving from Personal to Transpersonal Love
Let's think of the brahmavihāras (the divine abodes of friendliness, compassion, joy, and equanimity) as aspects of "unconditional positive regard"—the phrase coined by psychologist Carl Rogers to describe the judgement-free supportive environment most conducive for healing.
The heart of the brahmavihāras is to make this feeling universal, beyond liking and disliking, personal or group relatedness, or other affinities. So let's call it "transpersonal."
Seen in this way, the BVs are less about healing our individual attachment patterns or our preferential ego states as regards other people, but transcending our ego preferences and states entirely. In a not-spiritually-bypassing way, of course.
How do we do this?