Unit Price In "price Slider" (Blocklayered)

[Nolo92i]

Hi !

I am using prestashop 1.6.1.1.

I am searching a way to filter by unit price instead of product.price in blocklayered module.
Any idea?

For example :
- I am selling a t-shirt at a price X
- I sell another T-shirt in pack of 3 at a price Y

Now the slider only proposes me to filter by price X and Y

I would much prefer to filter by unit price.
So... having the filter listing X and Y/3

Does anyone has an idea ?
Many thanks!