The United States Environmental Protection Agency (EPA) screens thousands of chemicals primarily to differentiate those that are active vs inactive for different types of biological endpoints. However, it is not feasible to test all possible combinations of chemicals, assay endpoints, and concentrations, resulting in a majority of missing combinations. Our goal is to derive posterior probabilities of activity for each chemical by assay endpoint combination. Therefore, we are faced with a task of matrix completion in the context of hypothesis testing for sparse functional data. We propose a Bayesian hierarchical framework, which borrows information across different chemicals and assay endpoints. Our model predicts bioactivity profiles of whether the dose-response curve is constant or not, using low-dimensional latent attributes of chemicals and of assay endpoints. This framework facilitates out-of-sample