If you mean having something like Transaction Time (secs): 0.17 [avg], where avg changes when the control changes, I think that at the moment unfortunately you cannot do it.
There are other workarounds, but I think that it’s too much effort.
Try have a look at this one: Toggle Between Overlapping Visuals in QuickSight Using Parameters or Controls
You can overlap different visuals, each one will be related to a specific aggregation.
Then you switch btw visuals based on the control.
By doing so, you can avoid generating a dynamic calculated field which changes aggregation based on the control/parameter.
You will just show a different visual and then you can select the aggregation directly in the visual configuration and the select “Show Aggregation” in the Visual Tooltip Properties.
Longer, but if necessary… 
Andrea