Taiyang Xiao Long/Affiliation

Qrow's Team
Taiyang was a member of Qrow's Team.

Yang Xiao Long
Taiyang's elder daughter with Raven Branwen. Though not much is known about their interactions, the two seem to have a happy father-daughter relationship. Yang also seems to have at least a slightly better relationship with him than Ruby, though hers was likely strained by Taiyang's concealment of the identity of her biological mother.

Ruby Rose
Taiyang's younger daughter by Summer Rose. Their relationship seems a little strained, as he's implied to be overprotective and she was clearly annoyed when Yang talked like him about making friends and growing up. Nevertheless, the two seem to have a happy father-daughter relationship.

Qrow Branwen
Qrow and Taiyang were once on a team together, along with Summer Rose and Raven Branwen. Both of Taiyang's children refer to Qrow as their uncle, suggesting either kinship or a close relationship, though the precise nature of the former is unknown(but the fact that he shares the same surname as his first wife, Raven, might be a factor).

Raven Branwen
Raven was one of Taiyang's teammates, along with Qrow and Summer Rose. The two at some point entered into a relationship that resulted in the birth of his first daughter - Yang. Shortly after her daughter's birth, Raven disappeared and is still missing in the present. Their interactions with each other are unknown, but from Yang's description of how he reacted after losing Summer, it can be assumed that he loved her greatly and was devastated when she disappeared.

Summer Rose
Summer was Taiyang's teammate, along with Qrow and Raven. Sometime during the first two years following the disappearance of his first significant other, Yang's mother, Taiyang entered into a relationship with Summer that would result in the birth of his second child - Ruby. Not much is known about how the two interacted, but after her presumed death he was said to have "shut down" as a result, likely meaning he loved her greatly.