query doc

docs/query.md

@@ -44,3 +44,8 @@ From left to right :
 
 
 ## Linking entities
+
+To query on a linked entity, simple click on a suggested node. The linked node will be surrounded in a red circle, and the list of attributes on the right-hand side will change to show the new node's attributes.
+
+!!! info
+     Linking entity A (after filtering on parameter A1) to entity B (filtering on parameter B1) in the interface create the following query : *List all entities A who match parameter A1 , AND are linked to any entity B matching parameter B1*