Question: Welcome Home was written by a former member of a boy band - where was that band formed?

Context articles: Welcome Home Tour
CNCO
Boy Band (TV series)
Jolin Chien
₩uNo
Backstreet Boys
Welcome Home (You)
Titanium (band)
Welcome Home (Brian Littrell album)
Uhuru (album)

The Welcome Home Tour is the fourth and current headlining concert tour by American country music group Zac Brown Band, and it is in support of their fifthe studio album "Welcome Home" (2017).
 The tour beagan on May 12, 2017, and will finish on October 27, 2017.
CNCO is a Latin American boy band formed on December 13, 2015, composed of Christopher Vélez, Richard Camacho, Joel Pimentel, Erick Brian Colón and Zabdiel de Jesús"."
 They won a 5-year recording contract with Sony Music Latin after becoming the winning competitors of the first season of "La Banda."
 The band toured with Ricky Martin and their singles, "Tan Fácil" and "Quisiera", charted well soon after their debut.
 They released their first album, "Primera Cita" on August 26, 2016.
 In August 2017, they became the first boy band to reach one billion views in YouTube, with their single "Reggaetón Lento (Bailemos).
Boy Band is an American television music competition series that premiered on June 22, 2017 on ABC.
 The 10-episode first season features young male vocalists competing to become a member of a new five-piece boy band.
 The final five boys who form the boy band receive a recording contract with Hollywood Records and perform the band's debut single during the finale.
 On August 24, 2017, it was announced on the live show that Brady Tutton, Chance Perez, Drew Ramos, Sergio Calderon, and Michael Conor were the new members of the boy band, In Real Life.
 They performed for the very first time their first single, "Eyes Closed".
Jolin Chien () is a Taiwanese singer, actor and model.
 He formerly went by the western name Samuel Chien.
 He was discovered while competing in a singing competition.
 He is a former member of the dual boy band group StyLe and current co-leader of Taiwanese boy band .
 He and his group members were under Avex Taiwan for their music management and currently under Chou’s Entertainment for their acting and commercial management.
Woo Ji-seok (Korean: 우지석 ; born May 11, 1990), commonly known as Taewoon or ₩uNo is a South Korean singer, rapper, songwriter, and record producer.
 He is a former member of the South Korean boy band Speed and former member of the South Korean Coed group Coed School.
The Backstreet Boys (often abbreviated as BSB) are an American vocal group, formed in Orlando, Florida in 1993.
 The group consists of AJ McLean, Howie D., Nick Carter, Kevin Richardson, and Brian Littrell.
"Welcome Home" also known as "Welcome Home (You)" is a single by Backstreet Boys member Brian Littrell.
 It was the first single from his first solo album "Welcome Home", and it was written by Littrell and Dan Muckala.
 Littrell wrote his part in Vienna, Austria when he was touring with the Backstreet Boys.
 This song was also featured in the compilation album "WOW Hits 2007".
Titanium is a New Zealand pop boy band formed in Auckland in 2012 from the winners of "The Edge" radio station's competition to create New Zealand's second boy band.
 The Edge radio station hosted auditions across New Zealand and eventually six young men were selected for the group consisting of members, Zac Taylor, Andrew Papas, Jordi Webber, Shaquille Paranihi-Ngauma, Haydn Linsley and T.K Paradza.
 They released their debut single, "Come On Home".
 The single debuted at number one on the official New Zealand Singles Chart on 17 September 2012.
Welcome Home is the debut solo album by Backstreet Boys member Brian Littrell.
 The album was released on May 2, 2006 on Sony BMG and Christian music label Reunion Records.
 The album peaked on the "Billboard" 200 at number 74, and at number 3 on the Christian Albums chart.
 Four singles have been released from the album: "Welcome Home (You)", which charted at number one on the Christian Songs chart, and won Best Video of the Year of Dove Award.
 The album has sold over 100,000 copies in U.S as of April 2007.
Uhuru is a bootleg version of the album "Welcome Home" (1975) by British Afro-pop band Osibisa, released without authorisation in 1992 by Soundwings Records (MC-102.1076-2) and distributed by Serenade S.A., Barcelona, Spain.
 The CD duplicates the "Welcome Home" album (in poorer fidelity) with the addition of one track from Osibisa's live video.