This is a randomized, open-label, phase Ib study to assess safety and efficacy of sacituzumab govitecan plus nivolumab or sacituzumab govitecan plus a fixed dose combination of nivolumab and relatlimab in patients with programmed cell death-ligand 1 (PD-L1) positive (defined by combined positive score \>10), metastatic, triple negative breast cancer on routine testing with one prior line of cytotoxic chemotherapy with pembrolizumab in the metastatic setting. The study treatment will be continued until the progression of disease, unacceptable toxicity, death, or withdrawal of consent for any reason.