Hello,

I think you misunderstand the feature of Show in Cateogies, this categories field selects the categories to where you want to show these attributes, please see and read this note under the Field: https://ibb.co/T08Cq79

This field is not for selecting the attributes, the attributes will auto-show when you select the Filter type and Attribute here: https://ibb.co/RHJVQG3

Now you will ask why the For Rent attribute is not showing under the Buying option dropdown here: https://ibb.co/j57s1FD Because you have not assigned any product to the For Rent attribute: https://ibb.co/k6smbxw You should at least assign one product then it will auto show under the Buying Option dropdown on the frontend.

I hope you can understand it now.

Best Regards.