Background

I wanted to create a view which lists all nodes of different content types that link to the current node displayed on the page. The nodes link via node reference. Since node references only work in one way, and I wanted to get the node references of different content types linking to the current node, I couldn't (didn't know) how to achieve this easily with just a plain view.

The solution I came about was to embed a view to display the different nodes that link to the current one, and feed that view a list of node ids of the linked nodes.