How to set the width of Category dropdown in runtimeProperties (Categorized Entity)

Hello,
I am using the runtimeProperties for dynamic attributes. And i can format the width of dynamic attributes using fieldCaptionWidth and fieldWidth. But i cant set width of the Category dropdown. Please guide how to control the width of the category dropdown. I have attached the image for better understanding…

Thank you…Capture

Hi,
Could you provide the xml for your screen?