You need to spend some time reading about Tree Displays in the Scripting Guide. When an object is moved to a Journal, to reference it, you now have to point to the journal, and then go to the location under the Journal, which will be different than in the Report Output. See the script below
Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/big class.jmp" );
dt1 = dt << Logistic( Y( :sex ), X( :height ), By( :age ) );
jour = New Window( "The Journal", <<journal );
// The Logistic platform generates a separate brance in the Tree structure
// for each By Group, therefore they each have to be moved
For( i = 1, i <= N Items( dt1 ), i++,
Report( dt1[i] ) << journal
);
// The Tree Structure is changed once you move the output to the Journal
// It is no longer 5 branches, but is instead one long branch, with
// multiple Iterations, Whole Model Test, etc.
// Deleting them this way, removes first one, which makes the
// second one now the first, which is deleted during the next
// loop of the For() loop
For( i = 1, i <= N Items( dt1 ), i++,
Jour["Iterations"] << delete;
Jour["Whole Model Test"] << delete;
Jour["Fit Details"] << delete;
Jour["Parameter Estimates"] << delete;
);
Jim