Hi,

You can use UID to get the login user in XML ,

<field name="user_id" string="Related User" domain="[('id', '=', uid)]"/>

That does not work in a case where I would like to compare a field with the same field value of current user, something like this : ('field', "=", current_user.field.id)

I would like to compare not user_id field but another field of the current user with the same field in the current model, something like this : ('field', "=", current_user.field.id)