Filtering Workforce Trend Real Time by item in Worker Assignment Real Time

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Has anyone had success filtering workforce trend real time data by a data point in Worker Assignment Real Time? I want to report on the make up of our officer population over time but when I apply a filter based on officer title (a descriptive flex field at the assignment level) the data does not change. 

I've tried adding in a measure from the Worker Assignment Real Time subject area and making sure Dimensionality is checked off - this has had no impact.