Auto populate title field based on Path browser path selection

To auto-populate page title in a title field based on path value selected in path browser field, you can refer following code snippet-

$(document).ready(function() {
    var textInput;
    var textToInput;
    var inputText;
    var ui = $(window).adaptTo("foundation-ui");
    var s = $(document).on("dialog-ready", function() {
        textInput = $('.js-coral-pathbrowser-button').parent().prev();
        textToInput = $('.js-coral-pathbrowser-button').parent().parent().parent().parent().parent().parent().parent().find("input[name='./page'].coral-Form-field");
      
        $(document).on("click", ".js-coral-pathbrowser-confirm", function() {
            setTimeout(function() {
                inputText = $(textInput).val();
                //$(textToInput).val(inputText.substring(inputText.lastIndexOf("/")+1).split('.')[0]);
                if (!$(textToInput).val()) {
                    $(textToInput).val(inputText.substring(inputText.lastIndexOf("/") + 1));
                }
            }, 1000);
        })
        $(document).on('click', '.js-coral-pathbrowser-button', function() {
            textInput = $(this).parent().prev();
            textToInput = $(this).parent().parent().parent().parent().parent().parent().parent().find("input[name='./page'].coral-Form-field");
        })
        $(document).on("change", " .js-coral-pathbrowser-input", function() {
            inputText = $(this).val();
            if (inputText.indexOf("/content") > 0) {
                textToInput = $(this).parent().parent().parent().parent().parent().parent().parent().find("input[name='./page'].coral-Form-field");
                
                if (!$(textToInput).val()) {
                    $(textToInput).val(inputText.substring(inputText.lastIndexOf("/") + 1));
                }
            }
        });
    });
});

Change the field selector input[name='./page'].coral-Form-field as per your dialog configuration where the title value is to be auto-populated.

You need to put the above code in a clientlibs JS file with the category "cq.authoring.dialog".