How to nest data regions for one dataset?

This should be a common problem and easy solution.  But I have tried many solutions I've seen posted online and most were for previous versions of SSRS.  How can I nest one child table within a parent table?  I don't want to use subreports because of its inefficiency.  Instead I want to pass the parent key value to this child.  This is what my structure resembles:

Employee1 
  Height
  Weight
  Eye Color 
Employee2 
  Height
  Weight
  Eye Color 
Employee3
  Height
  Weight
  Eye Color 

So the employee is the parent and then I want each employee to have these same attributes.  So I have a parent key and a child key that these link on.  How do I achieve this?

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Ryan D