Passing selectedField Location between Stacks

[Bernard Devlin]

I have two stacks.  Stack T contains text fields, and Stack B contains buttons.

Whilst typing in Stack T, if the user requires input from Stack B I want the
user to be able to just click on an item in Stack B, and have the text
associated with the clicked button inserted at the place in the field in Stack T
where s/he was typing.

My understanding is that it is the use of two stacks that is preventing me from
using the selectedField or selectedChunk to determine where the label of the
button should be placed.  Is this correct?