https://learn.microsoft.com/en-us/dotnet/api/microsoft.xrm.sdk.metadata.entitymetadata.manytoonerelationships?view=dataverse-sdk-latest
EntityMetadata.ManyToOneRelationships Property (Microsoft.Xrm.Sdk.Metadata) | Microsoft Learn
Gets the array of many-to-one relationships for the entity.
propertymicrosoftxrmsdkmetadata