In the SysML-1.6+ version of the Webel Parsing Analysis recipe for SysML®, in which a Snippet as parsing container extends the ElementGroup, this requirement is not met:
A form of relatability can be partially achieved using attributes (for "tagged values") on the custom stereotype Snippet extension of ElementGroup. For example, 'contradicts' and 'contradictedBy' attributes can be used to indicate when one sourced text extract contradicts another, as discussed in detail as part of this dedicated tutorial trail:
Hopefully, in SysMLv2, direct relationships will be possible via the v2 AnnotatingElement:
Visit also: SysMLv2: On the v2 Comment extension of the v2 AnnotatingElement as a candidate Parsing Analysis Container
This restriction in SysML1.6+ is also discussed in this video: Screencast: The LogicalWrapper: A proposal for a new element for UML and SysMLv1.x and SysMLv2.