I have 4 restaurants and each restaurant has it's own table
I seriously doubt that I'd use 4 separate tables even then. I might have some "detail tables" that are different, but keep a common table with data for each restaurant in that common table and then this issue does not occur.
And that's your best option here. If you can set up a common table, even if it is a table related to the layout's table, you can set up a single (relationship based) conditional value list by linking the values table to this common table and selecting the common table as the "starting from" table.
Otherwise, you'll need to set up multiple conditional value lists each based on different table occurrences in your relationship graph.
I've been debating back and forth of using one common table or the four. The restaurant was more a scenario. The actual picture is a table of libraries
I have four areas of materials I bring into the prisons; books, articles, electronic media, study guides/workbooks.
I then like to have portal of each on a course's profile page where under books I can have all the books for that class, all the articles, etc and see all with out having to filter
I do think one common is best though some fields would be empty like in the case of an article there are no ISBN numbers.
Since there appears to be no easy solution or it just was my lack of knowledge I'll go with the approach you suggested and see if I can over come some of my concerns
Yes but the example still holds. Even though these are different types of materials, you can still set up a common table for all of them. And you can still get your portals to work even though all refer to the same table (or at least the same Source Table).
There are two variations to this approach to consider. The simplest is just to define enough fields to cover the needs of all four material types and not use the fields that don't apply to a particular type when creating a record for that type. The other is to set up one table with all the fields that are common to all four items (even if this is only a Title field and a primary key field) and then you link in 4 "detail" tables for the data specific to that material type.
With either format you can set up layouts that are specific to just one type if that helps with the data entry tasks.
I'll play around with both approaches this weekend. The latter one seems like the one I'd like to go with but will see how things go in the devlopment