Problem

We are using the Plugin in Optimizely CMS to easily connect Optimizely Forms to Salesforce Marketing Cloud Data Extensions. This works very well when the user that's used to configure the connector only has access to 1 Business Unit (MID) in Salesforce. However, as I understand from Salesforce, many customers work with instances that have multiple Business Units. This means that from Salesforce stand point, you need to provide to which Business Unit you want to connect when authenticating, but the plugin does not provide a means to specify this. To solve this, we now had to create multiple users in Salesforce, each only able to connect to one of their Business Units. This increases the costs of the implementation, because each user is an additional license.

Suggested solution

When authenticating a user using the API in Salesforce, you can provide an account_id to specify to which Business Unit you want to connect within the instance. Information about this can be found here.
Add an optional field to the default set of fields when configuring a connector, where an MID can be specified. Use that value for account_id when authenticating to Salesforce.

This way, whenever a user has access to multiple Business Units (MIDs), the same user can be used for different connectors, connecting to any available Data Extension.