Script and extract layer to file

You stated you want the script to save the output files in the same folder the PSD is in.  You need to use the export Layers to Files functions to bypass its dialog.  Its a Plug-in script you can see that in the script code there an // BEGIN__HARVEST_EXCEPTION_ZSTRING section.  So if you record it in an action the action will hard code the output folder into the action step and when the action is played the action will pass the output folders and all the other dialog settings to the script and the script will use these settings and not display its dialog so the cation can be used is a batch process,  This is exactly what you want to do in your Script but you want to pass a different output folder for each PSD processed. So that is what you do in your script.    Here is a script the will pass the same folder all the time.  However, I made the export function have an output parameter.  All the other export layer to files dialog setting are hard coded the way I wanted. The function should give you some food for thought.  It saves gpg files.

var exportFolder = "~/Desktop/exportedlayers";
var makeFolder = new Folder(exportFolder);
makeFolder.create();

exjpg(exportFolder, activeDocument.name);

function exjpg(saveTo, preFix) {
  // Export Layers to Files
    var desc1 = new ActionDescriptor();
    desc1.putString(app.charIDToTypeID('Msge'), "Export Layers To Files action settings");
    desc1.putString(app.stringIDToTypeID("destination"), saveTo);
    desc1.putString(app.stringIDToTypeID("fileNamePrefix"), preFix);
    desc1.putBoolean(app.stringIDToTypeID("visibleOnly"), false);
    desc1.putDouble(app.charIDToTypeID('FlTy'), 1);
    desc1.putBoolean(app.stringIDToTypeID("icc"), true);
    desc1.putString(app.stringIDToTypeID("jpegQuality"), "10");
    desc1.putBoolean(app.stringIDToTypeID("psdMaxComp"), true);
    desc1.putString(app.stringIDToTypeID("tiffCompression"), "TIFFEncoding.NONE");
    desc1.putString(app.stringIDToTypeID("tiffJpegQuality"), "8");
    desc1.putString(app.stringIDToTypeID("pdfEncoding"), "PDFEncoding.JPEG");
    desc1.putString(app.stringIDToTypeID("pdfJpegQuality"), "8");
    desc1.putString(app.stringIDToTypeID("targaDepth"), "TargaBitsPerPixels.TWENTYFOUR");
    desc1.putString(app.stringIDToTypeID("bmpDepth"), "BMPDepthType.TWENTYFOUR");
    desc1.putBoolean(app.stringIDToTypeID("png24Transparency"), true);
    desc1.putBoolean(app.stringIDToTypeID("png24Interlaced"), false);
    desc1.putBoolean(app.stringIDToTypeID("png24Trim"), false);
    desc1.putBoolean(app.stringIDToTypeID("png8Transparency"), true);
    desc1.putBoolean(app.stringIDToTypeID("png8Interlaced"), false);
    desc1.putBoolean(app.stringIDToTypeID("png8Trim"), true);
    executeAction(app.stringIDToTypeID('6f1c2cf5-4a97-4e32-8f59-f5d7a087adef'), desc1, DialogModes.NO);
};

Hi,

Since you have said you have written a script to export layers. So in your script you should show dialog to select the path for teh exported images. And you want that path must be the path of current document. So, you need to create a simple dialog, using Adobe ScriptUI. 

Please try below sample code how it will work. This below code show you dialog and allow you to choose the folder on clcik of "Select" buton and if the photoshop document is saved, by default it will have path for that document.

#target photoshop
function showDialog() {

    var dlg = new Window("dialog", "Sample Dialog");
    try {
        var psdPath = app.activeDocument.path;
    } catch (e) {

    }

    row = dlg.add('group', undefined, '');
    row.add('statictext', undefined, "Path: ");
    var pathInput = row.add('edittext', undefined, "");
    pathInput.enabled = false;
    pathInput.preferredSize = [350, 22];
    if (psdPath)
        pathInput.text = decodeURI(psdPath);

    //Icon button
    var selectButton = row.add('button', undefined, 'Select', {
        name: 'Select'
    });

    selectButton.onClick = function () {
        if (psdPath) {
            var folder = Folder(psdPath);
            var folderPath = folder.selectDlg("Select a folder to save the files");
        } else {
            var folderPath = Folder.selectDialog("Select a folder to save the files");
        }
        if (folderPath) {
            pathInput.text = decodeURI(folderPath.fsName);
            goButton.enabled = true;
        }
    };

    var buttonGroup = dlg.add('group', undefined, '');
    buttonGroup.alignment = 'right';
    var closeButton = buttonGroup.add('button', undefined, 'Close', {
        name: 'Close'
    });

    closeButton.onClick = function () {
        dlg.close();
    };

    dlg.show();

}

showDialog();

Before running the above snippet, open your current photoshop document so that it amkes you clear what exactly needs to be done.

Let me know if this helps you to understand.

Thanks

Charu