Allow users to update their gravity form single unique entry - php

Question

I am trying to make a form which will allow them to update their entered unique entry. Suppose there is form which is used to collect, the User Specializations
And this Specializations field is gravity forms multiselect field which is dynamically set. And as they update their specializations also updated in entries tab.
So, i just want to allow they to have this multiselect field updation.
I came across a solution to add multiselect choice dynamically but that only populate the field with all the choices not the user selected also.
So, is there is way to set the user entered choices dynamically?
Possible Solution:
Like we can get the entries and then set search criterion to current user and will get a unique entry and then after we can set these selected values in the choices.
Issue Exists with the above possible solution:
but still there is issue like it will be creating new entry as form dont know it is update operation. So can anyone help?
//Auto Populate Service Field in Form ID=
add_filter('gform_pre_render_2', 'populate_services');
add_filter('gform_pre_validation_2', 'populate_services');
add_filter('gform_pre_submission_filter_2', 'populate_services');
add_filter('gform_admin_pre_render_2', 'populate_services');
function populate_services($form)
{
foreach ($form['fields'] as &$field) {
if ($field->type != 'multiselect' || strpos($field->cssClass, 'populate_services') === false) {
continue;
}
$services = get_specializations();
$choices = array();
foreach ($services as $service) {
$title = stripslashes($service->name);
$choices[] = array(
'value' => $service->ID,
'text' => esc_html($title)
);
}
// update 'Select Duration' to whatever you'd like the instructive option to be
$field->placeholder = 'Select Services';
$field->choices = $choices;
}
return $form;
}