It is done by Ministry of Spain; here are the sources ;

Private Hospitals The private hospitals in Spain are managed by private healthcare providers. These hospitals are often smaller as compared to public hospitals. In addition, they also offer more specialized services. Some private hospitals in the country include Clínica Universidad de Navarra, Hospital Universitario Quirón Madrid, HM Universitario Sanchinarro/ CIO Clara Campal, Hospital Universitario Sanitas La Zarzuela, Centro Médico Teknon – Quironsalud, and Hospital Universitario Sanitas La Moraleja. 

Public Hospitals Public hospitals in Spain are operated by the government, and they can be further classified into three major categories: general hospitals, mid-level hospitals, and high-technology hospitals. They are classified based on the level of care that they provide to their patients. Some of the public hospitals in Spain are Hospital General Universitario de Alicante, Hospital Universitari Vall d’Hebron, and Hospital La Paz. 

The University of Barcelona (UB) offers a Master in Advanced Nursing Clinical Practice program. Selection criteria include: Previous skills and knowledge in the program’s specialization areas, Professional experience in the program’s specialization areas, Academic transcript, Reading and comprehension skills in English, and Personal interview

Registration Prior to being able to work as a foreign nurse in Spain, you must first register with the Professional Nursing Association, which is located throughout the country. It is important that you register in the area where you will work. The requirements per association may vary from one another. The documents that are often required are listed below. * Official degree certificate * Original and photocopy of Academic certificate * Certificate of your specialization (if any) * 2 photographs  * Original and photocopy of National identity document  * Bank account number (for the payment of fee) * Proof of payment

Where to apply for degree recognition in Spain

: https://www.educacionfpydeportes.gob.es/servicios-al-ciudadano/catalogo/general/05/051270/ficha/051270.html

https://www.expatica.com/es/education/higher-education/qualifications-in-spain-104884/#where-to-apply

You can apply for degree recognition in Spain at the following places: * The Spanish Ministry of Education and Vocational Training (MEFP). This is the best way of making an application, as the MEFP is the department responsible for authorizing recognition. You can apply through the MEFP website or through one of the registries in Madrid. * The Spanish embassy or consulate in your home country. * Any Spanish government office that serves as a public registry office at the national, regional, or local level.