Look for Nested XML tag with Regex

Look for Nested XML tag with Regex

This is my first post here, hoping to get some response. I've read through
few similar posts and consensus is not to try parsing xml/html with regex
but what I'm asking seems to be easier than the ones on other postings, so
i'm giving it a shot.
I'm trying to find all the nested tags, here are some examples I want to
catch: <a><a></a></a>
I don't want to catch <a></a><a></a>
So in plain english I want to catch all <a> following other <a> without
having </a> in between them..and I want to look though the entire string
so i should proceed even it sees a newline or linebreak
Hoping to have this problem solved. Thanks all!