Thank you for contacting us and I'd be happy to assist.
To automatically select the current 'edition' post in the relationship selection field, you can add the "[wpv-post-id]" shortcode to get the current post's ID, in that field's "Field default value".
( example screenshot: screenshot-visual-form.png )
Note: if your form is set to use the expert mode, you can pass the current post's ID through the "value" attribute:
[cred_field firstname.lastname@example.org' class='form-control' output='bootstrap' select_text='--- not set ---' required='false' value='[wpv-post-id]']
I hope this helps and please let me know if you need further assistance.