Which design pattern should we use for category of tenants / users?

Existed Code - We can perform CRUD on tenant and also we have business method for same in business layer. Who can perform actions against tenant - Restricted to two users (Role_A & Role_B). TenantController -> TenantService -> TenantDAO

New Scenario - Now we are introducing tenantCategory so older tenants will be known as Tenant_A and new tenants will be known as Tenant_B.

What we did - Used If else in same TenantService code and did what was required for new use case.

• Skip few fields
• Added few new fields
• Added new validations
• Did authorization in same method using if else as initially we were allowing two users (A & B).We used @PreAuthorization but for this new tenant only B can perform the actions.

What can be do better - Can use design pattern to separate the flow. I did some research and get to know suitable design pattern are -

1. Strategy
2. Decorator
3. Visitor

But still not sure which one is suitable pattern.

Techstack - Java 11 & Spring Boot