Ezra was from the tribe of Levi, never heard of the tribe of Kohen.
Maybe the Nethinims are from the tribe of Kohen.
A Kohen is a descendant of the family of Aaron, the brother of Moses, who was designated for the priesthood. All Kohanim belong to the tribe of Levi, but not all Levites are Kohanim.
The Netinim were descendants of the Canaanites who surrendered to Joshua (Joshua chap. 9) and designated as "hewers of wood and carriers of water." They performed menial chores for the Levites. Their genealogy is listed separately from that of the Jews.
These poor folks are under the delusion that you can tell who the Jewish priests are simply by matching up last names using the "sounds like" method (Cohen, Kohen, Kohan, Cohan, Cohen, Cohon, Cohn, Kohn, Kohen, Koehn, Koehne, Kohin, Kohns, Cones, Kohan, Koen, Koens, Cohem, Coham, ...).
The only true records on Jewishness, tribal affiliation, etc were destroyed thousands of years ago with the last earthly temple and the last authentic priesthood.
Anyone can adopt the name "Cohen" or one of the variants. There is no way today to tell conclusively if such a person is truly descended from Aaron.
Of course it really does not matter. Inclusion among the people of God is not according to race, but rather according to relationship with the true Seed of Abraham, Jesus Christ. If one is "in Christ" then one is a true child of Abraham.
The Aaronic priesthood has passed away forever. As the Scripture teaches speaking of Jesus, "As He also says in another place: 'You are a priest forever According to the order of Melchizedek'." (Heb. 5:6) Those who follow Christ share in that eternal priesthood. "You also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ." (1 Peter 2:5)
Lindsey and Co. continue to put stock in a physical priesthood that has forever passed away.