Is there any option in ShaerPoint Designer 2013 workflow to access Active Directory "Manager" field?
So that we can get the manager of a user specified in particular field.
You're using SharePoint 2013 - got it.
If your workflow is a SharePoint 2010 workflow you can simply use the Lookup Manager for User activity.
If your workflow is a SharePoint 2013 workflow you will need to use the Call HTTP Web Service activity, with the following end point URL:
You can find full details here.
I have posted a detailed instructions for getting the current user and the user's manager in SharePoint Online. I have also added a link for the JS and custom form for download. Get Current Logged in User & Manager using REST API in SharePoint Online
REST API Call:
var url=_spPageContextInfo.webAbsoluteUrl + "/_api/SP.UserProfiles.PeopleManager/GetMyProperties"