I'm sorry, but I don't understand the question. Without seeing exactly what you've already built, it would be impossible for me to tell you how to fix / change it. If you have an existing report based on a query that gets its criteria from a normal single-select listbox then yes, you're going to have to completely rewrite it. Is what you're asking how to create the proper SQL to generate a report based on a multi-select listbox? If that's the case, then I can definitely show you how to do this in the next Developer class.

I'm sorry if I'm bad at explaining, I'm working in Training section, we have a personal Training Tracker that we send it to Managers to in inform each manager about his and employees whose working under him training statues.  I've already created a report that can be specified each section in our company based on a multiselect list box in a form using a query. we already exporting reports as PDF but it's a huge number if we wanted exporting each employees. when I watched the video, you created a link through properties to select the ID number from text box. as for me I established this connection through query that gets its criteria from a normal single-select list box. so what the SQL to Generate and export individually PDF for this sort report?

OK, I see from your account that you only have Access Developer 17 (this class). You're missing the lessons on multi-select listboxes and recordsets that came before this, so you don't understand how to properly parse the multi-select listbox. So you'll need to go back and watch the previous classes (Developer 15 and Developer 16) where I explain how to use a Recordset and read the items in a multiselect listbox. That's the only way to properly loop through the items you've selected in the listbox one at a time and do something (like export a PDF). You can't do it with just a query and a report. You need to loop through the selected items and export the reports individually.