Scatter chart bubble size with field parameters

Hi all,

I am looking to create a scatter chart with bubble size that corresponds to the number of observations that have a given combination of values. I found a measure PhilipTreacy made to do so in this post:

https://community.powerbi.com/t5/Desktop/Scatter-Chart-Bubble-Size/m-p/1706419

Bubble Size = CALCULATE(COUNTROWS('Table'), FILTER(ALL('Table'), 'Table'[CycleTimedays] = SELECTEDVALUE('Table'[CycleTimedays]) && 'Table'[DaysSinceCompleted] = SELECTEDVALUE('Table'[DaysSinceCompleted])))

However, my x and y axis are both field parameters so the user can select the variables to go on each axis. I have one parameter for each axis. How can I make this measure work with field parameters? 

One thing I have tried is SELECTEDVALUE('Parameter'[Parameter Fields]) to refer to the column, but then I would need another SELECTEDVALUE wrapped around that to get the specific value in the scatter chart.