The allowed range for a given relationship attribute is represented by members in MRCM attribute range reference sets. The referenced component of an attribute range member is a concept from the Attribute hierarchy. Where this rule is applicable can be looked up by the MRCM attribute domain reference set which has a link to the MRCM domain member in which this attribute is applicable.
Each attribute range member also has an Attribute Rule field, which describes the whole rule, including its domain, attribute, cardinality, and range constraints in a single ECL expression. This field, too, helps to see the applicable context for any given range member.
Attribute range members define the applicable range in an ECL expression under the Range constraint property. This expression may include several clauses separated by the OR operator as can be seen below.
For more information regarding MRCM attribute range members see the official documentation.