Interpersonal 'Between'

Between you and me	the hand-waver and the mentally ill guy	were	talking	absolute rubbish
comment Adjunct: secrecy	Subject	Finite	Predicator	Complement
	Mood		Residue

Non-Spatiotemporal 'Between'

they	drank	all the wine	between them
Actor	Process	Goal	Accompaniment

the contest	is	between British and Iraqi lawn bowlers
Carrier	Process	Attribute: circumstantial: accompaniment

Halliday & Matthiessen (2014: 324):

Accompaniment is a form of joint participation in the process and represents the meanings ‘and’, ‘or’, ‘not’ as circumstantials;