I have a search engine created on my page with filters.
The problem comes because I have more than 70 categories and i want to insert a accordion between categories radial selectors.
It wouldn't be too difficult where you have several filters to hide some of the filters (e.g. "advanced filters") within an accordion, but you are describing hiding just part of a single filter, which is rather different.
You would need a bespoke solution for this.
Essentially you would need to use JS (or jQuery) to modify the markup of the filter section, moving some of the checkbox inputs inside a div that you then controlled the visibility of using some button you add.
If you are not comfortable programming that yourself, you will need to ask a developer to do it for you, it's outside the scope of support to provide such custom solutions.