I am am trying to create a custom filter only particular pages in the storefront. I have a collection which will show all the products present but, I need a custom filter only for this PLP. Please do let me know how I can achieve this.
If you are talking about the default (collections/all), maybe you can try some apps in order to achieve it.
https://apps.shopify.com/ultimate-search-and-filter-1
This one can create different filters for different collections (default collection included)