Showing a collection sorted by data from a dropdown list


I am building a website with a standard presentation of employees pulled from a collection. Every employee also have different specialities attached to them. Thees are pulled from a different collection as a multireference… all working fine.

In the top of the site I have a dropdown-list pulling all theese different specialities (pulled from the collection - it is not showing in webflow but works on my link to the exported site) But now I like to make it possible to select a speciality from the drop down menu and have my collection sorted by that… How do I do that?

Maybe someone could just tell me how to just get the Collection URL that Webflow generate itself, so I could work with this parameter… that would help a lot.

Thanks in advanced

Here is my site Read-Only:

Here is the page.