Navigate to Manager Home > Configuration > Special Pricing. Click on the Adv Options button to the right of the tree of offers.
The 2nd option on this screen is 'Use Net or Gross Sales in Labor Sales Calculations'. Choose your preference and save.
You'll see the results in several places, including the Manager Home Sales Summary and Labor % Graph:
The Store Summary Labor section:
The Labor Sales Report:
The Trend Report:
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