The answer to this question is provided by the European Commission.

The correct sequence for the calculation of the Market risk concentration sub-module of the standard formula is the following:
(1) As a principle, all individual exposures to counterparties that belong to the same corporate group are treated as a single name exposure and are assigned a credit quality step in accordance with Article 182 of the Delegated Regulation (EU) 2015/35.
(2) The weighted average credit quality on the single name exposure is calculated in accordance with Article 182(4) of the Delegated Regulation (EU) 2015/35 and the exposure at default on the single name exposure (Ei) is calculated in accordance with Article 182(3) of the Delegated Regulation (EU) 2015/35.
(3) The relative excess exposure threshold (CTi) pursuant to Article 185 of the Delegated Regulation (EU) 2015/35 and the risk factor (gi) pursuant to Article 186 of the Delegated Regulation (EU) 2015/35 are calculated on the basis of the weighted average credit quality on the single name exposure as calculated under step (2).

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The answers clarify provisions already contained in the applicable legislation. They do not extend in any way the rights and obligations deriving from such legislation nor do they introduce any additional requirements for the concerned operators and competent authorities. The answers are merely intended to assist natural or legal persons, including competent authorities and Union institutions and bodies, in clarifying the application or implementation of the relevant legal provisions. Only the Court of Justice of the European Union is competent to authoritatively interpret Union law. The views expressed in the internal Commission Decision cannot prejudge the position that the European Commission might take before the Union and national courts.