Communicate relation between two table

Communicate relation between two table

At this time, I'm able to create a relation (1:M) between two table or geometries. After, I user Identify tool to exploit the relation. It is only possible to use this feature when your Identify tool is done on one (1) geometry.

Here my question: Is it possible to select multiple geometries in parent table (select by attribute or location) and communicate to the child table the same selection based on their common attribute (pk,fk).

QGIS 2.8

A partial answer using selection (not relation) has been published for this question. Question on