ISO 9001:2015 4.3: Determining the scope of the quality management system
The organization sets the scope of its QMS by deciding where the system's boundaries lie and what it applies to, taking into account the issues from 4.1, the requirements of the relevant interested parties from 4.2, and its own products and services. Every requirement of the standard that can apply inside that scope is applied. A requirement may be treated as not applicable only with a justification, and only where leaving it out does not reduce the organization's capability or responsibility for making products and services conform and for raising customer satisfaction. The scope is kept as documented information that names the products and services it covers and justifies each requirement judged not applicable.
This control maps to 14 controls across 14 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.