Aroon Oscillator - how to setup the parameters?

Hello,

I want to use Aroon Oscillator in MT4. The default parameters are the following:

AroonPeriod - 10
Filter - 50
CountBars - 300

I tried to adjust the oscillator to my trading system as I changed the parameters,
but I am not sure how to determine the exact values. I trade XAU/USD with
time frame 15 min. Can you please tell me which are the best parameter values
for this time frame ? Also is there any formula to calculate these parameters for
any other time frame like 1 hour or 1 day ?

I think you need to figure out the best parameter values for yourself as different traders/strategies will have a different set of parameters.