How do I prevent additional inputs appending to the url (in groups)?

[CisForChi]

Hi there! This has been so helpful, thank you so much. I'm just wondering how I could toggle the user selection in the groups, for example, my values are color, size, type. If someone chooses one colour, then another, how do I remove the first colour value on select? It seems to continuously append to the url. Thanks so much :)