Grep output between XML nodes "Pattern within the main node set"

I am wondering if there is any way to accomplish this. XML Format:

<Main>
<Master>
<Node1>Content</Node1>
<Node2>qwerty</Node2>
<Node3>854789</Node3>
<Node4>999999</Node4>
</Master>
<Master>
<Node1>Content</Node1>
<Node2>qwerty</Node2>
<Node3>123456</Node3>
<Node4>999999</Node4>
<Node5>qwerty</Node5>
<Node6>123456</Node6>
<Node7>999999</Node7>
</Master>
<Master>
</Master>
<Master>
</Main>

If i use Grep to search for 999999 What i would like, is the whole Node set from to to be printed. But the Nodes can have different number of lines (Its not fixed) One could have 5 the other could have 20 So i cannot use something like: Grep -HrnA10 -B10 "9999999" As this would end up printing other node sets and make viewing the data confusing.

I have thousands of XML Files, so i am querying the files first with find to only pull up the first 30 days worth of files.

example:

find . -name "*.xml" -type f -mtime -30 -exec grep --colour=always -HrnA13 -B20 -E 'Pattern' {} \;

An example of the output, If i searched for "854789" I would like to see this output:

<Master>
<Node1>Content</Node1>
<Node2>qwerty</Node2>
<Node3>854789</Node3>
<Node4>999999</Node4>
</Master>