Persistence BDM in multiple pools

Hi,
I have a problem with a Business Data Model that I use in a parent process and in a called process. I tried to set the mapping but I can’t get the value of the object on the called process (the object on the called process stays null).

Also I don’t have a contract because I use the Bonita 6.x legacy form.

It is correct to assing the mapping using the “assigned to data” option?