Well, depending on what you're trying to see... if it's ssl encrypted, you won't find much, without first either having the certs to decrypt the traffic, or doing an arp man-in-the-middle for the ssl session.
If it's not SSL, then it depends, again, on what you want to narrow it down to. Do you have one IP address in mind, to grab traffic from, and want to eliminate others? You can filter on ip.addr == ipaddress (where ipaddress is the target IP you want traffic to and from) or if you know both ends, you can do the same thing twice, with && in between, to catch all traffic between the two IP's. You can also experiment with port filters, if you KNOW everything you want is on 80, or another port.
It's all stuff you'll need to practice and play with. If you're not used to doing traffic analysis with Wireshark, there are numerous books, online tutorials, and even paid CBT and video learning courses for it. Laura Chappell's stuff is excellent to learn from. Well worth the time and money, if you can afford them.
~ hayabusa ~
"All men can see these tactics whereby I conquer,
but what none can see is the strategy out of which victory is evolved."
- Sun Tzu, 'The Art of War'
OSCE, OSCP (Former - GPEN, C|EH - both expiring / expired)