Liebenberg was twice selected to represent Boland at the annual Under-18 Craven Week tournaments; in 2012, he played for them at the tournament held in Port Elizabeth and he once again played in 2013, captaining the side and scoring two tries in their match against the hosts in Polokwane.
After finishing school, he made the move to Pretoria to join the, following in the footsteps of older brother Wiaan who made the move three years earlier. He represented the side in the 2014 Under-19 Provincial Championship, quickly establishing himself as a key player for the side. He started thirteen of their fourteen matches during the campaign, scoring seven tries as the Blue Bulls made it all the way to the final of the competition, where they lost to in Cape Town. Despite not having played any first class matches, Liebenberg was selected in the ' 55-man wider training squad prior the 2015 Super Rugby season. He also made the cut for the final squad and was named on the bench for their Round Two match against the in Pretoria. He made his debut, coming on as an injury replacement for Deon Stegmann in the first half, but ended the match on the losing side, with the Hurricanes running out 17–13 winners. In March 2015, Liebenberg was named in a South Africa Under-20 training group as part of their preparation for the 2015 World Rugby Under 20 Championship. He featured for them in a friendly match against a Varsity Cup Dream Team in April 2015.South Africa U/20"> In May 2015, he was included in the South Africa Under-20 squad that toured Argentina. He started in their second tour match, captaining the side and scoring a try in a 39–28 victory. Upon the team's return, he was named as captain of the side for the 2015 World Rugby Under 20 Championship. He started all three of their matches in Pool B of the competition; a 33–5 win against hosts Italy during which Liebenberg scored one of South Africa's tries, their match against Samoa which once again saw Liebenberg score a try in a 40–8 win and a 46–13 win over Australia to help South Africa finish top of Pool B to qualify for the semi-finals with the best record pool stage of all the teams in the competition. Liebenberg started their semi-final match against England, but could not prevent them losing 20–28 to be eliminated from the competition by England for the second year in succession and also started their third-place play-off match against France, helping South Africa to a 31–18 win to secure third place in the competition. In June 2015, he extended his contract at the Bulls until October 2017. During December 2018 and January 2019 he played for Stade Français in France's Top 14on loan.
