You didn't say where you want the selections to be displayed so I assume a current selections box will do. You can just set an action in the Text object properties that sets a variable value. That variable can be used to conditionally show or hide the current selections box.
If you want the selections to show in the text box itself then create the variable but instead of using a current selections box just put an IF statement in the Text of the text box. Something like this: if(VTest = 'True', GetCurrentSelections(', '))