The next step is to map the <publication> element in MergedLibrary to the <publication> element in FilteredLibrary. When you connect the output connector of MergedLibrary with the input connector of FilteredLibrary, the following notification message is displayed: "You have created multiple target components in the mapping project. To preview the output of a specific target component, click Preview button in the title bar of that component, then click the XSLT, or Output tab, to preview the result." Click OK. Notice that new buttons are now available in the upper-right corner of both target components: (Preview) and (Pass-through). These buttons will be used and explained in the next steps.