Type the name of the material in the text box of the tool, autocomplete will help you to find the exact name of the material, after that click on "Select" button and any element using that material will be added to a new selection.

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10) and uninstall as you would any other application from your system.

In railing elements, only the material of the balusters will be considered.