Metropolitan Valentine was a priest of the Moscow Patriarchate who joined the ROCOR when communism ended. He became a bishop in ROCOR.
There was a controversy about parish registrations in ROCOR in Russia as the Church grew and new communities from the Moscow Patriarchate left and joined ROCOR as communism ended.
Ultimately, Metropolitan Valentine (then Bishop Valentine) refused to cooperate with the Synodal decision. His position was that to comply would have jeopardized the status of the parishes in the eyes of the State and risk loosing them. He ceased attending the Synod meetings and they suspended him.
There was a brief reunion afterward, but it failed. Finally in 1995 he made a final break. At some point in this process, he had ordained some bishops, and ROCOR deposed/defrocked him (said he is no longer a bishop). He claimed the deposition was invalid and carried on with running the ROCOR parishes in Russia that stayed loyal to him.
Eventually, his Synod of bishops elected him Metropolitan. This is not recognized by ROCOR or the other Churches of Worldwide Orthodoxy. From the ROAC's point of view, they don't care, because they believe the ROCOR violated its principles and faith by joining the Moscow Patriarchate in 2007. ROCOR naturally does not agree with this assessment.
That is the very abbreviated and oversimplified version of the story. I'd suggest you research the documents from both sides to get a better understanding of the issue. They are available on the internet in many places.