Reply To: Apply Multiply Effect and Clipping Path then Group images.

This should work:

//Ari S. - designerjoe@outlook.com
app.scriptPreferences.enableRedraw = false;
// 'Undo' will undo the entire script
app.doScript(main, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, "Image Manipulation Script");

function main(){
    // Capture the current selections in array
    var mySelections = app.selection;
    // Capture all the paths from the selected PSD
    try {
        var paths = mySelections[0].pageItems.item(0).clippingPath.photoshopPathNames;
        var myDialog = app.dialogs.add({name:"Select PSD Clipping Path", canCancel:true});
        with (myDialog) {
            with(dialogColumns.add()) {
                with(dialogRows.add()) {
                    staticTexts.add ({staticLabel:"Select the clipping path that you want:"});
                    with(dialogRows.add()) {
                        var myPathDdl = dropdowns.add({minWidth:100});
                        myPathDdl.stringList = paths;
                        myPathDdl.selectedIndex = 0;
                        }
                    }
                }
            }
        }
    catch(myError) {
        alert("Make sure it's a PSD");
        exit();
        }
    
    if (myDialog.show() == true) {
        for (var i = 0; i < mySelections.length; i++) {
            try{
                var bottomObject = mySelections[i];
                var topObject = bottomObject.duplicate();
                bottomObject.transparencySettings.blendingSettings.blendMode = BlendMode.MULTIPLY;
                try {
                    topObject.pageItems.item(0).clippingPath.appliedPathName = topObject.pageItems.item(0).clippingPath.photoshopPathNames[myPathDdl.selectedIndex];
                    topObject.pageItems.item(0).clippingPath.clippingType = ClippingPathType.PHOTOSHOP_PATH;
                    bottomObject.pageItems.item(0).clippingPath.clippingType = ClippingPathType.NONE;
                    try {
                        var myGroup = bottomObject.parent.groups.add ([bottomObject, topObject]);
                        app.select(myGroup);
                        }
                    catch (myError) {
                        // If it can't group
                        alert("could not group successfully");
                        }
                    }
                catch (myError) {
                    // If it can't apply the Photoshop path then it obviously does not have one
                    alert("Selected image does not have a Photoshop path applied")
                    }
                }
            catch (myError){
                // If it can't duplicate the object or apply multiply then it's obviously not a graphic frame
                alert("Make sure you selected a graphic frame");
                }
            }
        }
    myDialog.destroy();
    }