First it is important to note that both Business Continuity Management (BCM) policy and Disaster Recovery (DR) policy are top-level documents, covering management intentions. For operational purposes, i.e., detailed step-by-step activities and responsibilities, you also have to consider Business Continuity (BC) plans and Disaster Recover (DR) plans.
Considering that, the Business Continuity Management (BCM) policy is a more comprehensive document, covering management intentions regarding keeping processes and services running at minimum agreed levels after a disruptive event, and returning them to normal operation as quick as possible, while the Disaster Recovery (DR) policy focuses on management intentions regarding only the recovery of infrastructure (e.g., physical and IT infrastructure).
Reg arding documentation, you can have a single document to cover both issues, being the DR policy a section of the BCM policy.
These articles will provide you further explanation about BCM and DR in the context of ISO 22301, the ISO standard for business continuity management:
- What is ISO 22301 https://advisera.com/27001academy/what-is-iso-22301/
- The purpose of Business continuity policy according to ISO 22301 https://advisera.com/27001academy/blog/2013/06/04/the-purpose-of-business-continuity-policy-according-to-iso-22301/
- Disaster recovery vs Business continuity https://advisera.com/27001academy/blog/2010/11/04/disaster-recovery-vs-business-continuity/
- Business continuity plan: How to structure it according to ISO 22301 https://advisera.com/27001academy/knowledgebase/business-continuity-plan-how-to-structure-it-according-to-iso-22301/
This material will also help you regarding BCM and DR:
- Book Becoming Resilient: The Definitive Guide to ISO 22301 Implementation https://advisera.com/books/becoming-resilient-the-definitive-guide-to-iso-22301-implementation/