SV:Section Access separation in a transaction table without data island
First, Section Access is a very flexible tool, you can do vitualy everything. What you're asking about most likely is possible. I cannot tell you how to do it because it very much depends on the specific situation. The fact that data comes from multiple data source doesn't make much difference. Second, I don't know what loosely coupled tables or data islands have to do with it. In general, I recommend to avoid loosely coupled tables. The biggest problem with this feature is that it behaves differently in different QV versions, and all "work as designed".