It would help if you gave a screenshot of your domain model. But let's say you have a post entity and a reaction entity. The reaction entity is attached to the post entity with a multi to one reference. Then in the dataview of the post you could retrieve all the reaction over the association. When creating a reaction you need to make sure that you set the reference to the post object and set that reference otherwise the reaction would not be shown if you showed that post object.

Regards,

Ronald