Identifying the online marketing business capabilities and processes will help to understand the current state of the ecosystem and identify the areas where improvement is needed. For example, if the ecosystem does not have the ability to track leads or manage customer relationships, then these will be areas that need to be addressed.

Identifying the key organizational units, partners, and stakeholder groups that make up the online marketing ecosystem will help to understand the relationships between the different entities in the ecosystem and identify the dependencies between them. For example, if the marketing team relies on the sales team to provide leads, then this dependency will need to be considered when designing the new ecosystem.

The other two options, Identifying a suitable online marketing application that is better integrated with SAP CRM and ECC and can replace the existing one and Drawing an organization map highlighting the inter relationships and hierarchies amongst the above organizational units, partners, and stakeholder groups, are not as critical at this stage. The application can be identified and the organization map can be drawn once the business capabilities and processes have been identified and the key organizational units, partners, and stakeholder groups have been identified.

Therefore, the best course of action is to identify the online marketing business capabilities and processes and identify the key organizational units, partners, and stakeholder groups that make up the online marketing ecosystem. This will help to understand the current state of the ecosystem and identify the areas where improvement is needed.