Police say Deshaun Holton, who performed as Proof, got into an altercation with Bender at the CCC, an after-hours club on Detroit's Eight Mile Road, on April 11, and it escalated when shots were fired.
Holton, who was 32, was a member of the rap group D12, which also featured Eminem. He was the best man at Eminem's wedding in January.
In the lawsuit filed Tuesday in Wayne County Circuit Court, Bender's family said Holton was liable for attacking and wounding the 35-year-old Bender, who died a week later.
The lawsuit does not name a specific amount sought. An earlier lawsuit filed in the incident was dismissed.
Prosecutors say Bender's cousin, Mario Etheridge, shot Holton in an act of self-defense after Holton shot Bender.