any reference to the law of such State shall be construed, for the purposes of determining the law applicable under this Regulation, as referring to the law in force in the relevant territorial unit;
(b)
any reference to habitual residence in that State shall be construed as referring to habitual residence in a territorial unit;
(c)
any reference to nationality shall refer to the territorial unit designated by the law of that State, or, in the absence of relevant rules, to the territorial unit chosen by the parties or, in absence of choice, to the territorial unit with which the spouse or spouses has or have the closest connection.