Because sections are specific to
projects and are not shared between
projects, you can’t accomplish this
directly.
So what you can
do is use a custom field (you can also use
a tag) to in essence link the two projects
together, and then create rules in each
project.
I.e. in Project A
you create a rule like "If task gets moved
to Section ‘In Progress’, set the value of
custom field ‘Status’ to ‘In Progress’.
Then in Project B, you create a rule like
"If value of custom field ‘Status’ gets
changed to ‘In Progress’, move the task to
the ‘In Progress’ section.
Note that you
have to make sure the custom field is a
global one; that is, it lives in your
organizational custom field library.