multiple value selected in a combo box

I use a combo box as a filter.

          stFiltInstNo = "[idInstitution] = " & Me.filtInstNo & " AND "
          …
         Me.Filter = stFiltrer
         Me.FilterOn = True
   
 I would like to select multiple values in the combo box.

I tried to use MultiValued Field (MVF), but I don’t know how to extract values.
How can extract the values?

Is there a better way to do it?

Thanks