"The most Colombian of Colombian artists" is a descriptor self-bestowed by Fernando Botero, a figure whose legacy is a voluminous as the people, objects, and animals the 87-year-old has painted and sculpted for decades. The singular nature of that phrase is juxtaposed with the artist’s close-knit family life in the documentary “Botero.” The film, which has its European premiere at DocsBarcelona today, tracks the artist’s aim to “be a chapter in art history,” as one interviewee states, as he looms larger and larger in the art world—and at home.