This article describes how to use a calculated workflow. In this example I want to be able to access the current user on my customer entity.
Create a new workflow. And configure the following settings.
Name: Get CurrentUser
Root Entity Type: Customer
Value Type: Entity
Entity Type: Application User
2. Add the activity Set Workflow Return Value Activity and double click the branch. Set CurrentUser as the in parameter.
3. Go to the customer property and add a calculated entity where application user is the root entity.