Filter by shared reference [![enter image description here][1]][1]I have a content type of "School."
I have a content type of "Event" that contains an entity reference to "School" so that events can be linked to schools.
I can create a view block that filters by the school, when the block is placed on the node of the school, using contextual filters.

The problem:
Starting with the built-in "Basic Page," I added an entity reference to "School" so that "Basic Pages" can be linked to a "School," and be subpages of the "School."
How do I filter a view of "Events" that when placed on a "Basic Page" the "Events" block view will filter based on the entity reference, "Schools," that is shared between the "Event" and "Basic Page?"  I am looking to have an "Events" subpage that lists all the events of that individual school.
I am trying to avoid having to create separate block views that use filter criteria of each individual school.  I was hoping to use contextual filters.  

Thank you
You can, at least in D8 use "reverse entity references" in contextual filters and relationships, so what you propose should work.

Have a contextual reference grabbing the node id of the Basic page from the URL. A relationship from the page to the school comes next, then a reverse relationship looking for items that have a relationship to the School. You'll also add a filter on that second relationship, limiting it to Events.