Blur bellow element

[Nic727]

Hi,

 

I would like to know if I can blur an element that could affect an element bellow it.

For example, I would like my navigation bar to be white with opacity of 0.3-0.5 and blur it to make the element bellow be blurry. I tried very fast to do that, but only thing happening when adding filter blur to my navigation bar is that the text (menu) and nav bar are blurry, but not what's bellow (text, images, etc.).

I was trying to make something like the Fluent Design like Microsoft.

 

Thank you