Hey guys if a character with sharpshooter is adjacent to an opposing character can the sharpshooter shoot the melee character and 2 characters at a range? Assuming triple bolt of course. Does this Change if the character in melee has stealth?

First of all, there is no concept of "melee" in this game. I see people use the term and actually apply meanings to it, but it simply doesn't exist. A figure is either adjacent or not adjacent.

Secondly, a sharpshooter may only attack the opposing figures with whom he is adjacent. (There are exceptions, such as Energy Explosion and Pulse Wave, but they are special.)

So he can't target an adjacent and two non-adjacent characters with a single attack? Does it change if the ADJACENT character has stealth?

He cannot.
Adjacent is adjacent. It doesn't matter what the guy has.

Note that if the adjacent figure can use Stealth and the LoF to him crosses hindering terrain, then he cannot be targeted.

Thank you for your help!