How to extend attributes swatch and assign them multivalue

[GardeMM]

Hi guys,
I would like to introduce the possibility to use an attribute swatch as a multiselect. I know, this seem not sane, but I wouldn't know in how other way to realize customer's specification.

He ask me the possibility to filter products by color attribute (an attribute swatch) and that a product is shown when one of their attribute color is applied as filter.

For example:

I have a product double-colored, his colors are black and yellow.
Right now with traditional swatches i can specify only a color, i would like to assign 2 or more color at the same time. how could i do this?

Could you help me?

Thank you

[Rakesh Jesadiya]

You have to do your own logic for this process and its bit complicated. 

You can get same functionality from Free and Paid extensions of magneto2,

Free Extension:

Filtered Navigation Free Extension.

You can get Paid extension from Amasty Team with same functionality which you want.

If issue solved, click Kudos and Accept as Solution.