#...
lib.pageCategories = COA
lib.pageCategories {
    5 = LOAD_REGISTER
    5 {
        parentCat.cObject = TEXT
        parentCat.cObject {
            field = parentCat
            ifEmpty.cObject = TEXT
            ifEmpty.cObject {
                value.current = 1
                ifEmpty = 0
            }
        }

        pageUid.cObject = TEXT
        pageUid.cObject {
           field = pageUid
           ifEmpty.data = TSFE:id
        }
    }

    20 = CONTENT
    20 {
        table = pages
        select {
            languageField = 0
            uidInList.field = uid
            pidInList = 1
            recursive = 99
            selectFields = sys_category.uid as catUid, sys_category.title as cattitle
            join = sys_category_record_mm ON pages.uid = sys_category_record_mm.uid_foreign JOIN sys_category ON sys_category.uid = sys_category_record_mm.uid_local
            where = sys_category_record_mm.tablenames = 'pages' AND sys_category.sys_language_uid = '{GP:L}' AND sys_category_record_mm.uid_foreign = {register:pageUid} AND sys_category.parent = {register:parentCat}
            where.insertData = 1
        }
        renderObj = TEXT
          renderObj {
            field = cattitle
            wrap = <li><span>|</span></li>
        }
        wrap = <ul class="list-unstyled cats">|</ul>
    }

    90 = RESTORE_REGISTER
}
#...