Condition for evaluating a multiple selection of a segmenter

Hello, to see if you can help me with the following, I have a segmenter, in which there are paper books and digital books, what I need is a measure that evaluates when I have selected one or more digital books I get a message on a card confirming that the selection is Digital. When it is only one I have no problems but in the case of selecting several I do not find the solution. Here's a visual example of what I need:

Greetings and thanks in advance