The girls, who have not been named, remain in Maiduguri, the source said.
The militants herded the 276 girls out of bed at a school in Chibok in northern Nigeria in April 2014.
As many as 57 girls escaped and shared harrowing tales of fleeing from the nearby Sambisa Forest, believed to be the terrorist group’s stronghold.
Dozens are still missing, and their whereabouts remain a mystery, but are believed to be somewhere in the forest.
At the time, relatives roamed through the forest for days, frantically searching for the girls.
The kidnapping sparked global outrage and prompted global figures such as activist Malala Yousafzai and first lady Michelle Obama to support the campaign to #BringBackOurGirls.
Boko Haram recently split into two factions, one backed by ISIS.
The militant group says its aim is to impose a stricter enforcement of Sharia law across Africa’s most populous nation, which is split between a majority Muslim north and a mostly Christian south.
In previous videos from the militant group, its leader, Shekau has demanded the release of Boko Haram fighters in exchange for the Chibok girls.
No Boko Haram fighters were released in exchange for the girls, the source said. It happened as a result of a series of negotiations held at high level and involving a group from Geneva, according to the source.