London 2012 bronze medallist Alan Campbell will hope a strong showing in the single scull will help to secure a place at a fourth Olympic Games.
Enniskillen woman Nixon, 22, will be part of Britain's quadruple scull team.
The event is the last event ahead of the final Olympic qualifier in Lucerne.
Nixon, Tina Stiller, Jess Leyden and Rosamund Bradbury finished fourth at the World Cup regatta in Varese last month and will hope to be in the medals in Brandenburg.
"This weekend is going to give us more of a glimpse of what could turn up at the Olympic qualification regatta in Lucerne," said Nixon.
"I think things are going well so far. Having more time in the crew is always a positive and we are making the most of that time together.
"I feel really lucky each day I get to go out with the girls. I am learning so much from them."
Campbell, representing Britain for a 10th successive year, will be facing a strong field in the single scull.
"I've seen the entry list and pretty much everyone you would expect is there," said the 32-year-old.
"Ondrej Synek is there, he's a three-times world champion now, and what Croatia's Damir Martin did in winning the World Cup in Varese last month was pretty exceptional.
"There are also a lot of new guys coming through and some people who are still looking to qualify for Rio, so they will really be on their game."
Campbell's fellow Coleraine Olympic medallist Peter Chambers will compete in the lightweight men's four this weekend.
Chambers' brother Richard has withdrawn from the lightweight men's double scull with Will Fletcher as he continues his recovery from a hand injury but another Coleraine man Joel Cassells will be in action in the non-Olympic lightweight pair with Sam Scrimgeour.
Cassells and Scrimgeour are the defending world champions in the class.
Northern Ireland pair Holly Nixon and Alan Campbell will be among the British rowers aiming to press their claims for Rio Olympic berths at this weekend's European Championships in Germany.