Sitting Block (Filters) Inside Default Filters

Hey guys!

I try to compress website and there is a lot of free space between default filters. My questions is how to put a block (with product filters, horizontal) inside the template code. Exactly here:

I found it: @hungryweb made a good job: https://forum.cs-cart.com/topic/29828-a-simple-way-to-add-any-content-on-any-place-on-template/

I have problem because I am using Unitheme and some details I can hide by adding in User-defined CSS class another class: hidden-phone. When I use @hungryweb solution, I can't extend CSS class name. Any way to hide the block for phone version?

I found temporary solution, just edit tpl file filters, however I will appreciate for more smart solution without editing "core" files.