How to map permission of Dynamics 365 to SharePoint Online ?

No, there is no native out-of-the-box Microsoft feature that automatically replicates Dynamics 365 (Dataverse) record-level security to SharePoint Online permissions.

But you could try to use M365 groups, since SharePoint can use M365 groups as sitemembers, You could try to map M365 groups to Dynamics Dataverse roles. 

A M365 group or Microsoft Entra ID group can be linked to a Dataverse Group Team.

Create one or more Security Roles and assign them to the Group Team. All users who are members of the linked Entra ID group automatically inherit the permissions granted by those Security Roles.

Important long-term limitation: SharePoint unique permissions

Every time you secure individual folders or documents, SharePoint creates a unique permission scope.

Limitations or SharePoint are approximately 50,000 unique permission scopes per list/library

Scenario:

- 50,000 Opportunities

- 50,000 folders

- unique permissions per folder

You will encounter:

Slower permission calculations.

Longer indexing times.

Search performance impacts.

Administration complexity.

Potential platform limits.