Filtering on the search results page after an advanced search

Hey there,

Just after some help. We have a search box built with relevanssi that’s working great in finding the posts we want. The url that’s generated when all the fields have values in the search box is “example.com/?s=Legal+assistance+services&from=&to=&tag=219&report_author=109&cats=50%2C52”.

On the actual results page we’d love to have filters in a dropdown, specifically Tags and Authors. However, when selecting one of these the parameter gets added on the url and doesn’t actually replace the previous selection.

For example:

Let’s say the report author is 109 is John then they select report author 110 which is Sally after they’ve done a search, we’d like the report_author value to get replaced.
This “example.com/?s=Legal+assistance+services&from=&to=&tag=219&report_author=109&cats=50%2C52″ to this”example.com/?s=Legal+assistance+services&from=&to=&tag=219&report_author=110&cats=50%2C52”

What’s the best way to do this?

Thank you very much