# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/<div class="header-info-box">\K((?:[^<]|(?!<\/?div).|<div(?1)<\/div>)*+)/<div class="hello"><\/div>/gm;t' <<< "
<div class=\"header-info-box\">
Разный контент, <span> включая теги</span>
<div>
<div> </div>
</div>
</div>
"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html