Magento 2 add query to custom url

I’m working with multiple checkboxes of layered navigation. I have to use mail category Id to pass active and clicked params as a filter to URL.

In my plugin I override getUrl like this.

public function aroundGetUrl(MagentoCatalogModelLayerFilterItem $item, $proceed)
    {
        if (!$this->_moduleHelper->isEnabled()) {
            return $proceed();
        }

        $value       = [];
        $filter      = $item->getFilter();
        $filterModel = $this->_moduleHelper->getFilterModel();
        if ($filterModel->isSliderTypes($filter) || $filter->getData('range_mode')) {
            $value = ["from-to"];
        } elseif ($filterModel->isMultiple($filter)) {
            $requestVar = $filter->getRequestVar();
            if ($requestValue = $this->_request->getParam($requestVar)) {
                $value = explode(',', $requestValue);
            }
            if (!in_array($item->getValue(), $value, true)) {
                $value[] = $item->getValue();
            }
        }

        //Sort param on Url
        sort($value);

        if (!empty($value)) {
            $query = [
                $filter->getRequestVar()                 => implode(',', $value),
                // exclude current page from urls
                $this->_htmlPagerBlock->getPageVarName() => null,
            ];

            return $this->_url->getUrl('*/*/*', ['_current' => true, '_use_rewrite' => true, '_query' => $query]);
        }

        return $proceed();
    }

I need to pass this query to and build a URL with a custom URL like below

"http://localhost/magento/main/brands?2001"