Constraint path from other entity

Hi, anyone can help me on how to make the constraint path if the attribute from the other entity? Thank you.   For more understanding, On the new page, i fill in all this items.  Then, there is a button add line that will open a new page to key in the data.  On the new page, i want to select the area, but i want to make the constraint path take from the company, plant, department and division plant at the first page.  
1 answers

At first; if you specify an XPath on the selectable objects, it will execute a SQL to the database to retrieve the set of selectable objects.

thus when you have a new, not committed object in you page as context and you request a set based on a constraint related to that object, the database says no. Because the new object and thus the relation is not (yet) known at database level.

To solve this, use a datasource microflow instead or the constrained by function