It helps to have a self contained example to clarify the behaviour you want, so I've re-framed your question.
With the two commented-out lines , I guess is the behaviour you don't want. Does uncommmenting those two lines provide the behaviour you want?
browser := GLMTabulator new.
browser column: #myRoassal ; column: #mySelection.
browser transmit
to: #myRoassal ;
andShow:
[ : aGLMPresentation |
aGLMPresentation roassal
painting:
[ : view : numbers | |edges|
view shape rectangle ; withText ; size: 30.
view nodes: numbers.
view interaction noPopup.
view edges: numbers from: [ :x | x / 2] to: [ :x | x ].
" view edges do: [ :edge | edge model:#doNotSelectMe ]."
view treeLayout.
].
].
browser transmit
to: #mySelection ;
from: #myRoassal ;
" when: [ :selection | selection ~= #doNotSelectMe ] ;"
andShow:
[ : aGLMPresentation |
aGLMPresentation text
display: [ : selectedItem | selectedItem asString ]
].
browser openOn: (1 to: 10).