Custom drop down slicer visual

Hi All,

I have a requirement to create a custom slicer visual which should be a multi-select drop-down. I read the documentation and saw the sample slicer code (https://github.com/Microsoft/powerbi-visuals-sampleslicer). It is very hard to understand and convert it into my requirements. I'm from an HTML and JS background. Is there any simple examples which I can refer and documentation to understand how slicers work?

Right now I'm looking at https://github.com/jonbgallant/PowerBI-visuals-radioSlicer but still couldn't achieve what I need.