def printpdfmulti(layoutname):
    selected_layers = qgis.utils.iface.layerTreeView().selectedLayers()
    projectInstance = QgsProject.instance()
    layoutmanager = projectInstance.layoutManager()
    layout = layoutmanager.layoutByName(layoutname) #Layout nameprojectInstance = QgsProject.instance()
    for layer in selected_layers:
        qgis.utils.iface.legendInterface().setLayerVisible(layer, True)
        exporter = QgsLayoutExporter(layout)
        exporter.exportToPdf("C://data//" + layer.name() + ".pdf", QgsLayoutExporter.PdfExportSettings() )
        qgis.utils.iface.legendInterface().setLayerVisible(layer, False)


printpdfmulti("plane_view1")

qgis.utils.iface.legendInterface().setLayerVisible(layer, True)

QgsProject.instance().layerTreeRoot().findLayer(layer.id()).setItemVisibilityChecked(True)

def printpdfmulti(layoutname):
    selected_layers = qgis.utils.iface.layerTreeView().selectedLayers()
    projectInstance = QgsProject.instance()
    layoutmanager = projectInstance.layoutManager()
    layout = layoutmanager.layoutByName(layoutname) #Layout nameprojectInstance = QgsProject.instance()
    for layer in selected_layers:
        QgsProject.instance().layerTreeRoot().findLayer(layer.id()).setItemVisibilityChecked(True)
        layout.refresh()
        exporter = QgsLayoutExporter(layout)
        filename = "".join(i for i in layer.name() if i not in "/:*?<>|")
        exporter.exportToPdf("C://data//" + filename + ".pdf", QgsLayoutExporter.PdfExportSettings() )
        QgsProject.instance().layerTreeRoot().findLayer(layer.id()).setItemVisibilityChecked(False)


printpdfmulti("plane_view1")