When generating the following reports using default filters and display threshold is set to Yes, threshold is not shown in any of the reports.
Servers - Server Activity - Summary
Servers - Server Activity - Internal vs External
Servers - Server Activity - System Messages
In order to display thresholds, report must use the following filters:
Date | Must be more than a day
Detail Level | Daily
Display Options | Data and Graph
Trend and Forecast Options | Trend Only or Trend and Forecast
Display Threshold | Yes
Thresholds are shown in trend line therefore Graph must be enabled, and the 'Trend and Forecast line' must be set to on (either Trend only or Trend and Forecast). The trend feature is only a graph feature (not in the raw data).