Sadly that doesn't work. I will try to explain why.
I have many tables in the QlikView, 6 of which are all joined by the same complex join, made up of field A, field B, field C & field D. One of those 6 tables has another field, Flag1, which is the one I want to restrict by.
If I add Flag1 as a field in the 'section application' inline load, then this creates a new join from the data table to the section application table. In doing so, the join to the remaining 5 tables with this complex join gets messed up, making data in those tables available even though Flag1 has been successfully restricted.
So the restriction works but it messes up the data in all of the other tables whilst doing so. It has the same effect as restricting the SQL query for the one table, but failing to do a 'where in' statement to restrict all of the other tables at the same time.