I just had a quick look at your video. I don’t have a lot of time right now to explain too much, but essentially what you should be able to is make use of the User Profile row for the purpose of temporarily storing whatever values you need to create the extra relations. The way to do this is to modify the actions that take you to the various details screens, so that they first write the RowID of the selected item into a column in the User Profile row. Then because it’s in the user profile row, you can then access that value from anywhere.
Hopefully that helps a bit.
Also, take a look at the below video - it demonstrates a similar technique (but in a cleverer way):