Complicated 'double' contextual and relationships view I would like some help on how to implement the following view:
A block that shows all the 'events' happening at any 'location' created by a user.

I have 'event' and 'location' content types. There is a field in the 'event' node which refers to a 'location' node (it's nid).

I am familiar with views, just not sure how to get the 'double filtering' required to show only events that have a location that is created by the user logged in. I cannot create an 'author' relationship to a contextual filter for the location or event to a simple filter, as the view displays events, not locations... Any ideas?
I would create a View of the Content Type Location (these are the nodes created by your users, right?).


Create a Relationship to Author. 
Create a Filter to user: current and select Yes in Is the logged in user (NB: this a a regular filter, not a Contextual Filter)
Create a Relationship to the Event type through its reference field to Location (NB: select Entity Reference: Referencing Entity . If you select "Require this relationship" the View will limit the Location types to only those referenced in an Event node
Add any field to the View, but be sure to select the relationship you created in 3 above to show field from the Event type


That's it! Nice question!