var selectedFiles = File.openDialog ('Bitte Dateien wählen', null, true); 
 
var baseNames = []; 
 for(var i = selectedFiles.length -1; i >=0; i--){ 
var fileName = selectedFiles[i].name; 
if(fileName.indexOf('_') === -1){baseNames.push([fileName.substring(0, fileName.indexOf('.')), selectedFiles[i]]); selectedFiles.splice(i,i+1)} 
     } 
  
 var sortedFiles = []; 
 for (var b = 0; b < baseNames.length; b++){ 
     var myName = baseNames[b][0] 
          var tmpArray = [baseNames[b][1]]; 
      
  for(var i = 0; i < selectedFiles.length; i++){ 
      var fileName = selectedFiles[i].name; 
var baseOfFileName = fileName.substring(0, fileName.indexOf('_')) 
      if(baseOfFileName === myName){tmpArray.push(selectedFiles[i])} 
            } 
        sortedFiles.push(tmpArray) 
  } 

#target InDesign 
 
//pdf-preset für den export wählen 
 var myPreset = getPdfExportPreset(); 
 //Dateien auswählen 
 var selectedFiles = File.openDialog ('Bitte Dateien wählen', '*.pdf', true);  
 
//Basisdateien - alle Dateien ohnen '_' im Dateinamen - filtern 
var baseNames = [];  
 for(var i = 0; i < selectedFiles.length; i++){  
var fileName = selectedFiles[i].name;  
if(fileName.indexOf('_') === -1){baseNames.push([fileName.substring(0,  fileName.indexOf('.')), selectedFiles[i]]); }  
     }  
   
  //Schleife durch Basisdateien -> Abgleich mit allen Dateien nach gleicher Basis -> bündeln 
 var sortedFiles = [];  
 for (var b = 0; b < baseNames.length; b++){  
     var myName = baseNames[b][0]  
          var tmpArray = [myName, baseNames[b][1]];  
       
  for(var j = 0; j < selectedFiles.length; j++){  
      var fileName = selectedFiles[j].name;  
var baseOfFileName = fileName.substring(0, fileName.indexOf('_'))  
      if(baseOfFileName === myName){tmpArray.push(selectedFiles[j])}  
            }  
        sortedFiles.push(tmpArray) ; 
  }  
 
//Übergabe an Export 
for(var s = 0; s < sortedFiles.length; s++){ 
doStuff(sortedFiles[s])	; 
	} 
 
//Dokument erstellen, PDF platzieren, Zielordner erstellen, Export 
function doStuff(aFileArray){ 
var theDoc = app.documents.add(true, undefined, {documentPreferences: {facingPages:false, pageSize:'A4', pagesPerDocument:aFileArray.length-1}}); 
for(var p = 0; p < theDoc.pages.length; p++){ 
var thePage = theDoc.pages[p]; 
thePage.place (aFileArray[p+1], [0,0], undefined, false); 
	} 
var newFolderPath = aFileArray[1].path + '/' + aFileArray[0] + '/' 
Folder(newFolderPath).create(); 
var destFile = File(newFolderPath + aFileArray[0] + '.pdf'); 
 
with(app.pdfExportPreferences){ 
pageRange = PageRange.ALL_PAGES	 
	} 
 
theDoc.exportFile(ExportFormat.PDF_TYPE, destFile, false, myPreset); 
theDoc.close(SaveOptions.NO) 
	} 
 
function getPdfExportPreset (){ 
var pdfPresets = app.pdfExportPresets.everyItem().name; 
 
		var myDialog = app.dialogs.add({name:"", canCancel:true}); 
	 
	with(myDialog){ 
with(dialogColumns.add()){ 
		with(borderPanels.add()){ 
				with(dialogColumns.add()){ 
					staticTexts.add({staticLabel:"Bitte eine Pdf-Export-Vorgabe auswählen:"}); 
				}	 
				with(dialogColumns.add()){ 
					var pickedPdfPreset = dropdowns.add({stringList:pdfPresets, selectedIndex:0}); 
				} 
			} 
		} 
	} 
 
	if(myDialog.show() == true){ 
				var pickedPdfPreset = pickedPdfPreset.selectedIndex; 
				myDialog.destroy(); 
	return pdfPresets[pickedPdfPreset] 
} 
	else{ 
		myDialog.destroy() 
		exit(); 
	} 
  } 

var theDoc = app.documents.add(true, undefined, {documentPreferences: {facingPages:false, pageSize:'A4', pageOrientation:PageOrientation.LANDSCAPE, pagesPerDocument:aFileArray.length-1}});