How to properly organize this BEM sitebar?

Question

css

Answer 1

<div class="filter">
            <div class="filter__item form-el">
                <h3 class="form-el__title"></h3>
                <div class="form-el__input-row">
                    <input type="radio" class="form-el__input">
                    <label for="" class="form-el__label"></label>
                </div>
            </div>
            <div class="filter__item range-slider">
                <h3 class="range-slider__title"></h3>
                <!--   необходимые элементы для слайдера             -->
            </div>
            <div class="filter__item form-el">
                <h3 class="form-el__title"></h3>
                <div class="form-el__input-row">
                    <input type="checkbox" class="form-el__input">
                    <label for="" class="form-el__label"></label>
                    <span class="form-el__count"></span>
                </div>
            </div>
        </div>

I think it is possible and so. You can still think about the names of the blocks. Headings are generally better to make a separate block. It is also possible not to mix filter elements with input blocks.