Regular Expressions 101

(?s)applies the following effective flags to the remainder of the pattern: s

s modifier: single line. Allows a dot to match line terminators

<V>the literal text <V> (case sensitive)

.*?any character, repeated any number of times

</V>the literal text </V> (case sensitive)

.*any character, repeated any number of times

<V>the literal text <V> (case sensitive)

.*?any character, repeated any number of times

</V>the literal text </V> (case sensitive)

.*any character, repeated any number of times

<V>the literal text <V> (case sensitive)

Group 1(.*?)

.*?any character, repeated any number of times

</V>the literal text </V> (case sensitive)

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?s)<V>.*?</V>.*<V>.*?</V>.*<V>(.*?)</V>

New

Regex Explained: 
We often use the technique .*? similar as * in windows explorer search. 
In this example, we "know" that our input XML has exactly 3 V Tags and we want to know only the value of the third one. This is why we use () around the .*? at the end of our regex, it sets the first matchgroup to the third V Tag value. 
Here is our input XML:

<xml>
<V>ABCD</V>
<X>notused</X>
<V>FGEH</V>
<Y>notused</Y>
<V>3</V>
</xml>