local format = function(entry, vim_item)
    local kind = entry:get_kind()

    if vim.tbl_contains({ 2, 3 }, kind) then -- if kind is a Function (2) or Method (3)
        local start_index, end_index = vim_item.abbr:find('%(.*')
        if start_index then
            vim_item.abbr_hl_group = {
                { '@function', range = { 0, start_index - 1 } },
                { 'Comment', range = { start_index - 1, end_index } },
            }
        else
            vim_item.abbr_hl_group = '@function'
        end
    end

    return vim_item
end

format = function(entry, vim_item)
    local highlights = {}

    -- you will likely not want to get this query every single time for performance but this is an example
    local query = vim.treesitter.query.get(vim.bo.filetype, 'highlights')

    local success, parser = pcall(vim.treesitter.get_string_parser, str, vim.bo.filetype)
    if success then
        local tree = parser:parse(true)[1]
        local root = tree:root()
        for id, node in query:iter_captures(root, str, 0, -1) do
            local name = '@' .. query.captures[id] .. '.' .. vim.bo.filetype
            local hl = vim.api.nvim_get_hl_id_by_name(name)
            local range = { node:range() }
            local _, nscol, _, necol = range[1], range[2], range[3], range[4]

            table.insert(highlights, { hl, range = { nscol, necol } })
        end
    end

    vim_item.abbr_hl_group = highlights

    return vim_item
end,